Yu - Gi - Oh ! - Duel 021 " Digital Pet Duel " is the twentieth chapter of the " Yu - Gi - Oh ! " manga . This chapter was originally printed in the " Weekly Shōnen Jump " magazine in Japanese . Its first English release was in the Shonen Jump magazine . It has been reprinted in volume 3 of the and volume 2 of the bunkoban . Summary . Day 1 . Yugi narrates that keychain games are really popular at his school right now . A girl in front of him says that she forget to clean her pet ' s " poop " and it died . Her companion says that that is too bad . You have to clean - up after them every day . Yugi continues that Digital Pets are the most popular out of these games . They are simulation games , where you raise a creature on a miniature screen . In class , Anzu , Jonouchi and Honda gather around Yugi ' s desk . Jonouchi and Yugi ask how each others Digital Pets are doing . They admire Yugi ' s pet , who looks just like Yugi . Yugi says that he has named him U2 . Yugi remarks that it is strange that although this is just a game , one can get really attached to their pet . Yugi asks to see Jonouchi ' s pet . Jonouchi holds up his pet . Honda , Anzu and Yugi all make strange faces and Anzu says that it is so ugly . Jonouchi tells them to shut up , causing Honda to comment that it has got Jonouchi ' s bad attitude . Yugi mentions that it is said , that you transfer your personality to your pet , depending on how you take care of it . With the thousands of different creature types , Yugi says that there can be an infinite number of pets , all of which are unique . Yugi asks Honda if he has a Digital Pet . It is not his thing , Honda replies , he has got a dog at home , so he is too busy taking care of real pets to have time for digital ones . His dog just came into heat and has been driving him nuts . That is one thing you do not have to worry about with Digital Pets , he adds . Jonouchi gets excited when Yugi explains how pets can mate to share each others personality data . Jonouchi suggests that he and Yugi " mate right away " . Honda remarks that he did not need to hear that . Yugi and Jonouchi connect their pets . U2 is pretty wild , so Yugi hopes that he gets some of Jonouchi ' s wild personality . The two pets look at each other and Jonouchi ' s pet walks into U2 ' s screen , where he gives U2 a kick . The gang gasp in surprise and call it a bully . Anzu comments that the pet is just like Jonouchi . Jonouchi is ashamed of his pet and Yugi thinks that this may have been a bad idea . However the two pets start to get along and a noise is made to indicate that the transfer is complete . Jonouchi ' s pet moves back to his screen and Yugi and Jonouchi disconnect their pets . Jonouchi looks down at his pet , thinking that he needs to get some of U2 ' s cuteness . Yugi looks at U2 and asks what kind of data , he got from Jonouchi . Inside the device , a 3D version of U2 , looks up at Yugi thinking that this is his master . U2 starts acting scared as Kujirada approaches the group to show them his Digital Pet . Kujirada boasts that his pet is different from their ordinary pets . Jonouchi asks what makes Kujirada ' s pet different , jokingly asking if it is a thoroughbred . Kujirada goes on to explain about Hidden Characters . These are a rare kind of pet , with probability one in a million , he says and that they are said to exist due to a glitch or virus , but nobody knows for sure . Depending on how they are disciplined , fed , etc . they become a Hidden Character when everything is just right and he has one of these Hidden Characters . Jonouchi hates to admit it , but he would like to see . Yugi asks if they can look and Kujirada holds up his pet . Yugi and Anzu make unpleasant faces , while Jonouchi sniggers that it is uglier than his pet . Jonouchi asks how Kujirada knows that it is a Hidden Character ; the ultimate pet . Kujirada diverts their attention to the star in its graphics , explaining that it a trait that all Hidden Characters have . Normal pets do not live longer than 21 days , Kujirada explains , however his has been alive for 2 months already and calls it the ultimate pet again . Nonetheless Anzu maintains that all pets are special while they last . She does not think that his is so great , just because it can live longer . Kujirada smirks that she is just jealous . U2 starts to beep and Yugi looks at him , wondering why he has been acting so afraid . Night 1 . At Kujirada ' s house , Kujirada is woken during the night , by his pet , making noise indicating that it needs food . Kujirada mumbles that he just fed it five minutes ago and that he cannot sleep like this . He gives the pet food and realizes that he is even bigger than before . Kujirada is impressed by the rate it is growing . Inside the the device , the 3 - dimensional pet says that he is tired of eating pet food all the time . Kujirada looks at the pet , asking if it just spoke . He says that it is impossible as Digital Pets can only beep . The pet tells him off for calling him a pet . He points at Kujirada , saying " Fool ! You are the one who ' s the pet ! " He orders Kujirada to bring him more food , so that he will live longer and Kujirada will become famous because of him . Day 2 . At school , Jonouchi is horrified to find his pet ' s data is all gone . He tells Yugi that he left the room for a moment and his pet disappeared and shows him the blank screen . Elsewhere Kujirada laughs , having just fed Jonouchi ' s pet to his own . Kujirada ' s pet finds that other pets are more delicious than he thought . Although he just ate , he feels hungry again . He calls Kujirada and has a hypnotic effect on him , as he demands more food . Kujirada asks Anzu for her pet for a while . She refuses , but Kujirada snatches it from her and connects it with his pet . Inside the connected devices , Kujirada ' s pet grabs Anzu ' s pet , Peachy , and shoves her into his mouth , causing Anzu to wail out loud . Yugi saw what happened and Kujirada ' s pet demanded more food . Kujirada swipes U2 from Yugi and connects it to his pet , laughing that U2 should rejoice as he is about to become part of his ultimate pet . Inside the devices , U2 runs from the other pet . Despite its size , Kujirada ' s pet is fast and manages to catch U2 . He tries to eat him , however U2 ' s device makes a sound , indicating that it is about to grow . U2 changes to a form , resembling Dark Yugi . Kujirada ' s pet senses great power , before being punched by the powered - up U2 . Yugi , Jonouchi and Anzu are impressed with U2 defeating the other pet . Yugi realizes that U2 must have incorporated the data it received from Jonouchi ' s pet . Kujirada is stunned to see his pet beaten , but on the bright side , he sees that should at least be able to sleep . U2 ' s end . At night , Yugi watches U2 , thinking that all good things must come to an end . According to U2 ' s programming , he will disappear in the morning . Yugi tells U2 that he can eat as much as he wants and asks if he can watch him until morning , before saying goodbye . Appearances . Debuts are in bold . Anime adaption . Episode 7 of Toei Animation ' s " Yu - Gi - Oh ! " series is based on this chapter . Differences included :