Shoichi is one of the very few people Yusaku actively interacts with. The two are close friends and work together to fight The Knights of Hanoi. Yusaku shows trust in Shoichi's hacking abilities and even gave a brief smile when talking to him. Likewise, Shoichi hopes Yusaku can one day enjoy Dueling again. Shoichi also teases Yusaku about his poor social skills. Shoichi also acts as a guardian and an older brother figure to Yusaku mainly because Yusaku reminded him of his younger brother Jin. He is also shown to be concerned for Yusaku's well being especially when he duels.
It is heavily implied that Yusaku had a close friendship with Jin before they were involved in an incident 10 years ago and before the latter was kidnapped by The Knights of Hanoi. Yusaku is shown to deeply care for him and his disappearance is what made Yusaku fight for him and is determined to rescue him and save him for darkness.
Ai sees Yusaku as a partner, but Yusaku considers Ai to be nothing more than an object he needs to gain the upper hand against the Knights of Hanoi. He threatened to delete Ai in order to challenge a Knight, and ignored his pleas not to go back to VRAINS. Yusaku has little patience and annoyance for Ai's antics and often doesn't let him talk. Nevertheless, Ai supports Yusaku in his Duels, though he claims to do so out of a desire for survival. Ai also seems to enjoy teasing Yusaku, but knows when things get serious. Likewise, Yusaku follows Ai's advice when needed. Despite being rude to Ai and ignoring him most of the time Yusaku slowly grows to genuinely care about him; this was seen when Ai was deleted by Revolver's "Skyfire Prison" and he showed legitimate concern for him, showing that despite the rockiness of their relationship, Yusaku does view Ai as a friend and ally. He was also happy when Ai returned to his Duel Disk and playfully teased him for coming back to being a hostage.
Takeru Homura/Soulburner Edit
Souburner saved Playmaker from Bit and Boot while he was chasing Haru. The next day, Takeru was following Yusaku commenting that he's Playmaker. Yusaku at first didn't trusted Takeru since he was knowing his identity being Playmaker, but when Takeru explained that he's also victim from Lost incident, Yusaku changed his mind and gain Takeru's trust.
Yusaku seems to respect Flame a bit more than Ai. Yusaku agree to help Flame and Ai find their friends while investigating about the new enemies.
Aoi Zaizen/Blue AngelEdit
Aoi and Yusaku are classmates. She is unaware of Yusaku's identity as Playmaker but she seems to be suspicious of his identity as Playmaker after noticing he has the same duel disk as him and ask to check his deck in order to confirm his identity.
After Shoichi figured out that Aoi is "Blue Angel", Yusaku tried to get close to her in order to get a lead on Akira Zaizen and SOL Technology regarding his past memories. Aoi on the other hand believed Yusaku wanted her for her connections to SOL Technologies as many others had tried (which is technically correct, though not for the reasons she assumed) so she quickly dismissed him.
As Blue Angel, Aoi is shown to develop an interest and respect towards Playmaker since he saved her from Cracking Dragon. She is also shown to be very grateful towards Playmaker for saving her and she also went to his aid and saved him many times.
Yusaku is shown to feel guilty about what happened to Aoi as she fell under the Influence of the Hanoi Virus by trying to end the duel quickly. After she fell into a coma, he took her to the hospital and felt, due to the guilt, it was his responsibility to help her recover from her coma. After his duel with Revolver he asks Shoichi if Aoi is alright.
When they first met Naoki tried to befriend him but Yusaku showed little interest in Naoki and indirectly insulted Naoki with his observation. Despite this Naoki still continues to be friendly with Yusaku and often sits with him during class. Naoki is also a big fan of Playmaker unaware that he is Yusaku.
Yusaku is shown to have a deep grudge and hatred towards The Knights of Hanoi for what they did to his past and swore revenge against them and fights with them whenever they make an attack.The Hanoi in return consider Playmaker as a threat and plan to defeat him in order to take back Ai.
When first informed about a hacker named "Playmaker" who was defeating Hanoi members, Revolver initially suspected Playmaker was an agent from SOL Technologies but rejected the idea because SOL would act more publicly and dismissed Playmaker. It wasn't until Playmaker captured Ai that Revolver became interested in him. Revolver then switched all his efforts into defeating Playmaker before SOL did, as doing so was the only way to capture Ai. Playmaker, on the other hand, hates Revolver for being Hanoi's leader and vowed to defeat him and discover his true identity. During their first Duel, Revolver claimed that he wasn't interested in Playmaker's identity and considered him to be just another of the many people who hates Hanoi. It is heavily implied that the two have some sort of strong connection in the past.
Despite having a brief interaction with Yusaku at the hospital Akira is grateful to him for taking Aoi to hospital and mistook Yusaku as Aoi's boyfriend to which Yusaku stated that they are just classmates. However Akira initially hated Yusaku's alter ego Playmaker his hatred towards Playmaker has worsen when he thought Playmaker was responsible for putting his sister in coma he violently tortured him and refuse to believe him that it was Hanoi's fault until Revolver explained the situation. After reluctantly freeing Playmaker Akira pleaded him to save Blue Angel and fight for him even if the former hated him however Playmaker stated that he doesn't hate Akira and he only hates the Hanoi much to Akira's surprise. After Playmaker obtained the program from Revolver and cured Blue Angel from her virus which allows her to log out Akira is shown to be grateful to Playmaker for saving her.
At first Yusaku was indifferent and uninterested in Go. Go on the other hand is shown to be angry towards Playmaker for stealing his spotlight. After defeating Go Yusaku acknowledges him as a worthy opponent and started to respect his dueling style. When Shoich suggest him to recruit Go for their fight against Hanoi he stated that he doesn't want Go to get involved in this kind of danger out of concern he may get hurt.
Emma Bessho/Ghost GirlEdit
Both Emma and Yusaku aren't aware of their real identities. Emma is shown to have a great interest towards Playmaker and appears is hinted to have feelings towards him as she claim to Shoichi that he is charming and stated to him that moon is beautiful tonight in Japanese literature. She even indirectly stated that she is in love with him. Playmaker on the other hand is shown to not fully trust her even after she gave him the data bank