A Giver is a person who designs and presents puzzles for Solvers to challenge. There are many Givers in the series.
Jikukawa Souji is responsible for presenting the first puzzle to Daimon Kaito under the alias of "The Minotaur". Nobody knows this except Kaido Baron. A very gifted giver, Souji has made a number of puzzles. It is later revealed that Souji was a Solver who had also attempted the first puzzle, however upon completing the initial maze, he was rejected by the Orpheus Armlet, meaning he did not have the potential to become a Phi Brain. Distraught from this, it is implied that he is going to forget puzzles, until Kaido Baron comments on his potential as a Giver. Having found hope, Souji begins to work with Kaido Baron and "Section Phi" of the P.O.G in order to make puzzles and find potential Phi Brain candidates in Root Academy. Although he doesn't tend to follow Kaito and the rest of the group to different puzzles, he arranges transport and accommodation. While the group is focusing on their task, Souji usually also analyzes data and investigates the opponents in order to provide information to the group that normally helps them from being at a disadvantage. During the second season, Souji is contacted by someone else posing as The Minotaur, who tells him to rechallenge the first puzzle in order to obtain a Orpheus Armlet. Curious, he does this and is equipped with the second model of the Replica armlets. Intrigued to see the effects of the band and also to see how he would do against a real candidate for the Phi brain, Souji challenges Kaito to the cultivation of his work, the "Sliding Junction" puzzle, with the loss condition supposedly being bombs planted around the mountain. Although he initially stays composed, he briefly gives into the armband, but is beaten by Kaito and returns to normal. After this, he continues to support Kaito from behind the scenes.
Rook Banjou Crossfield
Rook is a P.O.G Giver and a childhood friend of Kaito's. Initially Rook is in control of his branch of the P.O.G and is watching Kaito as he progresses toward becoming a Phi Brain. Rook grew up at Crossfield Academy, a school for geniuses, and is experimented on from early childhood by the P.O.G to see his potential as a Giver. As such, he was isolated from the majority of the school and was confined to his own classroom and quarters. He frequently spends his time on breaks from the experiments in the forest, creating puzzles he genuinely enjoys and this is how he meets Kaito and the two both become friends. He and Kaito form a Giver - Solver duo, with Rook creating puzzles that finally challenge Kaito, and in turn Kaito taking his time to appreciate and accept Rook's puzzles. During this time, Rook promises to create a wood puzzle for Kaito, who states he can't wait to see it.One night however, Kaito keeps Rook out past his curfew and he is taken away, never to be seen until they are in highschool. The two reunite when Rook gives a puzzle on the whiteboard in Kaito's class. Later, Rook takes Kaito to an old maze they used to frequent at Crossfield Academy, where he leads Kaito to a Fool's Puzzle and reveals his "true nature". With his association with the P.O.G known, he begins presenting increasingly cruel puzzles to Kaito and his group to accelerate his progression. Eventually, he loses his composure after witnessing Kaito having "puzzle time" with Sakanoue Gammon(at this point he had become a P.O.G Giver after an offer from Elena Himekawa), becoming a laughing stock to the P.O.G. He finally challenges Kaito to his "Puzzle of God" on a secret island. The puzzle is built to ensure that if Kaito solves it, Rook plunges to his death. At the peak of his madness, Rook simplifies the puzzle to the point the solution is obvious so that Kaito can kill him. However, Kaito notices that the puzzle is based on the wood puzzle that Rook made for him as a child and thus manages to prevent the puzzle from crumbling instantly as he remembers the structural weakpoint. After Kaito saves him, and he finally rejects his Orpheus Armlet, he decides he needs to reform the ways of the P.O.G and sets off to do so. During the second season, Rook spends his time with Bishop investigating the Orpheus Order in many different locations and mostly solves puzzles. He does the same in the third season, investigating the Pythagoras Scriptures to find the true nature of the Puzzle of God. Eventually, he challenges Kaito to a final puzzle under the influence of another Orpheus Armlet provided by Orpheus himself. In this puzzle, they race round tracks in pods to go through gates which close after one person has passed. Although Kaito managed to time the first two so that they could pass at the same time, Rook reveals that he built the final gate on a single track, making it impossible for them both to survive. Breaking free of the Armlet, he lets Kaito pass and then crashes in the gate, causing the pod to explode.
Gammon is revealed to be both a gifted Giver and Solver. He creates his own puzzles under the alias "Chido Setsu" in order to provide financial income for him and his sister, for whom he cares deeply. His puzzles are held in much admiration, frequently being number 1 puzzles in many puzzle magazines. However, during times of doubt, critics note that his puzzles are lacking. Kaito, not knowing Gammon to be "Setsu", also notes that the puzzles are easy and void of feeling compared to what they normally are. During the first season, Gammon eventually betrays Kaito and the group to become a P.O.G Giver and finally beat Kaito. He devises many battle type puzzles for him, including a tower puzzle based removing steel girders from beneath your opponent and a capture grid duel(like the MySims Agents minigame). Eventually he rejoins the group, however becomes evident when they are under stress that they do not trust him as much.
Elena Himekawa is the presenter of the popular show "Puzzle Kingdom", a show where participants challenge her puzzles in order to win a cash prize. She is an idol figure, and thus many people support her, despite the fact that she is actually not a very nice person. She openly taunts, bullies and humiliates the contestants frequently. However this is just a facade for her true occupation as a P.O.G Giver. This is revealed when she is made to challenge Kaito by Herbert Muller, who controlled the P.O.G at that time. After she is defeated by Kaito, she recruits Gammon into the P.O.G During the second and third seasons, her personality begins to make a change and she begins to assist the group more, though this is mainly for Gammon.
Muller is a Giver in the P.O.G who is dedicated to defeating Kaito. He initially assigns pre-made puzzles to be presented to Kaito, however when these fail he resorts to presenting his own. His first puzzle for Kaito is a logic based puzzle in which he has to find out which colored gnomes are liars and which are telling the truth. However the puzzle is made with a vital piece of information necessary to solving it omitted, making it impossible for Kaito to come to a final solution. However, Jikukawa Souji intervenes and provides this information, allowing Kaito to defeat the puzzle and save Nonoha. He is then kicked out of the P.O.G for providing an unfair puzzle. He returns in season two, having worked a deal with Klondike and Whist, becoming the leader of Freecell and his companions. He oversees their actions and spectates while they each challenge a member of Kaito's group. When this fails, he kidnaps Elena and has Kaito and Nonoha battle Wu and Noh in a territory puzzle. Failing again, he resurfaces after the group learn of the Orpheus Order hideout, revealing his two replica rings. Here he challenges Kaito to another logic puzzle, based on crossing the river. He is again left empty handed when they succeed and Kaito tries to save him when the puzzle begins to collapse. Initially he begins to realize his mistakes, but the rings take over him and suppress his mind, causing him to seem as if he is still evil. After the Orpheus Order collapses, he later shows up in season 3, with 4 replica rings, provided by Enigma, and an even larger passion for vengance. He challenges Kaito to a final logic puzzle, where they must stand on a scale of which their weight is equal to a bag on the scale. However, he again withholds information about the fact that it is their weight plus a statue they were previously holding. Kaito deduces this and defeats him and then attempts to convince him to reject the Armlets. However his mind is almost overtaken again while this puzzle collapses. He eventually breaks free of their control and is saved by the group.
All members of the Orpheus Order challenge Kaito to puzzles. The first is a Mirror Maze given by Freecell. They then use both Airi Mizutani and Tamaki Chieno to challenge Kaito to puzzles; a stacking puzzle and a kind of Cat and Mouse puzzle respectively. Following this, they then challenge the group to a territory based puzzle, and a Rink Slider duel puzzle. After suffering defeat, Herbert Muller is appointed "leader" of the group. During this time, Melancholy challenges Rook to a maze (though she uses Lotte and Rummy to do the dangerous work), Mizerka and Eve challenge Kaito to a picture puzzle, and Pinochle challenges Kaito to a Colour matching puzzle with several levels of increasing difficulty, where the loser falls into a furnace. After all of these, Klondike challenges Kaito to a duel maze puzzle, where they must solve their opponents maze through trial, error and skill. Finally Freecell challenges Kaito to his "Puzzle of God" in the Himalayas, a tag style puzzle.
Kaido Baron was a P.O.G Giver assigned to partner with Makata Jin. The two make form a mutual relationship, with Kaido giving puzzles to enable Jin's development, with Jin in turn solving them quicker to help Kaido develop as a Giver. Not much else is known about his work as a Giver, although it is notable he is similar to Jikukawa in that he was not a potential Phi Brain and instead worked to develop others.
Makata Jin was a genius Solver who solved many Sage and Fool puzzles in order to progress toward the Phi Brain. Initially assigned to a partnership with Kaido Baron, he was given various puzzles. Though at first they were challenging enough, Jin's exponential growth rate lead him to find them too easy, prompting him to leave the P.O.G solve as many Fool's Puzzles as he could. Once finished with his goal he begins building many of his own Fool's Puzzles. Sometime during his absence, he met Raetsel and solved puzzles with her until he one day told her she is lacking something, leaving her behind. He later returned, and convinced Kaito(upon request by the P.O.G) not to "let go of what is important" as Kaito was going to give up puzzling, prompting him to mentor Kaito and Rook upon meeting them in another encounter. His final Fool's Puzzle was the "Killing Colosseum", a battle type puzzle in which the participants must try to climb out while avoiding high speed boulders and controlling the tracks. Although it was designed to lock in the loser so they meet their demise, there was a secret exit installed by Jin to ensure this wasn't actually the case, as he truly wanted it to be solved by both at the same time. Although not confirmed, it can be assumed that he probably gave many puzzles to Kaito and Rook, as well as Raetsel, during his time mentoring them as children.
Orpheus is a Giver, notably of the Puzzle of God. He is shrouded in mystery for the majority of the series and is only known as a historic figure. He was in fact a genius puzzler, and invented the Orpheus Armlets to be given to potential Phi Brain candidates. The Armlets allow the users to use more of their brains for the sole purpose of challenging puzzles and achieving the Phi Brain as he had, in order to challenge the Puzzle of God and "obtain the Divine Scriptures" which have the answers to everything. But, this is actually revealed to be a false incentive by the Pythagoras Scriptures. Orpheus reveals himself after Jin regains his memories following the "Killing Colosseum", in the body of Jin, whilst Rook reveals that the Puzzle of God is made to push two Phi Brain candidates to their limit, allowing Orpheus to download his sentience into their mind. Orpheus presents Kaito with many puzzles to advance his progress to the Phi Brain. He also presents Sakanoue Gammon with a Sage Puzzle, in which the treasure was an Armlet(which he later rejects) and the loss meant death in the void. After this he tells Raetsel she cannot become a Phi Brain without an Armlet and presents her with a puzzle where she can only traverse staircases downwards. Finally, after the boat puzzle designed to select the two best Phi Brain candidates, he presents Raetsel and Kaito with the Puzzle of God, a duel type territory puzzle which allows the participants to live through their pasts and alter them to how they see fit. However during this, Raetsel is taunted by the same outcome, where Jin says she is lacking something. She closes herself off by choosing a life without Jin, prompting Kaito to have to do the same to reach her mind. After they come back to reality, they battle and Kaito lets Raetsel win. She states that since Kaito solved the puzzle, but she won, he now doesn't know whose mind to hijack. However he proceeds to hijack Kaito's, only to be stopped by a device of Cubic's, which was planted earlier.
- Various members of the P.O.G are Givers, providing puzzles for Solvers to challenge and even taking requests from normal citizens to build their puzzles. They have challenged many including the entire of the Root Academy group.
- Enigma was a Giver for Lovushka, the woman he loved and Jin's rival. Her death in a Fool's Puzzle led him to hate puzzles
- Souji is the head of a Puzzle Club, in which various members such as Naoki Takeda and Airi Mizutani, work on puzzles. After being challenged, Kaito always solves their puzzles near instantly, much to their chargrin.
- In an attempt to relieve Gammon from his doubts, Kaito challenges Gammon to a puzzle based on one that Gammon used to mock him on their first meeting.
- Lotte made many mazes for his dog, Rummy.
- Eve, Ana's sister, challenges Kaito to a puzzle alongside Mizerka. The puzzle was a dark picture, depicting her feelings of malice toward Ana.
- Freecell's mother, Solitia, gave Freecell a pendant which was a puzzle, containing a picture of the thing most dear to her...
- Many of the children at Crossfield Academy present Kaito with puzzles. However he solves them all quickly and without interest, prompting them to avoid him.