Manjiro Sano/Relationships

Shinichiro Sano
Shinichiro is Mikey's older brother. He was many years older than Emma and Mikey, so he often took care of them in the absence of their parents. Shinichiro was Mikey's hero and the subject of his admiration, as he founded the strongest gang at the time and was their highly respected leader. When Shinichiro died, part of Mikey broke. He strived to continue his legacy. His deceased elder brother inspired him in many ways during his teen and adult years, leading him and so many around him to greatness in their respected areas.

Emma Sano
Emma and Mikey are half siblings close in age. Emma came to live with the Sano's at age 3 and they eventually became close. Mikey is protective of his sister and has a soft spot for her. When they first meet, he notices how lonely and out of place she seems. Thinking it's because her name is different from everyone else's, he says that he will now be called "Mikey" so he can have a foreign name like her. While that wasn't the reason why Emma felt distant at first, the gesture warms her heart and she appreciates her brother's naive kindness. Nowadays, they're very close to the point where the unsuspecting eye would think they were dating, as Takemichi mistakenly believes at first. After her death, he told her it was all wrong and it wasn't the life he thought she would get granted. Another part of his heart died with her.

Izana Kurokawa
Izana is Mikey's older adopted brother, who was briefly raised with Emma. Izana disliked Mikey out of jealousy, as Shinichiro would often talk about Mikey to him, but Izana wanted Shinichiro only to himself.. Izana wasn't raised with Emma for long; he was Emma's biological mother's ex-husband's affair, and was therefore not blood related to his mother at all. When he found out he wasn't truly a Sano, he broke. Shinichiro wanted Izana to become family with Mikey and Emma and live a happy, loving life with them. Mikey in turn was pleased at the prospect of having another brother and never harbored any ill intent toward Izana. After finding out how Izana turned out, Mikey wanted to set him free from his loneliness and save him, but Izana died before getting the chance at the Tenjiku vs. Toman fight. His last sibling to fall, the death of Izana leads to Mikey fully breaking. In the present timelines that result in Izana's death, Mikey adopts his hairstyle in order to keep his memory alive.

Friends
Hinata Tachibana

Takemichi Hanagaki
Mikey never met Takemichi in the original timeline. The two only meet by chance when Takemichi time leaps to the past, during which Takemichi challenges Masataka Kiyomizu from Kiyomasa's Gang to a 1v1. Noting Takemichi's bravery, he takes an interest in him by saying that "Takemicchi" will be his friend from now on. Later on, they become very close friends. Mikey has remarked that Takemichi is reminiscent of his deceased brother who, even though his fighting prowess was mediocre, was valiant in battle and was an excellent leader. Over time, Mikey comes to rely on Takemichi emotionally. He is the light that ensures Mikey will not fall to the darkness. Indeed, in one of the altered present timelines, Takemichi, for reasons unknown, had left Toman, which devastates Mikey, resulting in his fall to the darkness. He kills all his friends and becomes one of the present's most wanted criminals. Even so, the sliver of good left in Mikey at that point still desires for Takemichi's support, shown by the note slipped onto Takemichi's table in the present timeline that reveals his location. Mikey understands his sins and wants Takemichi to be the one to grant him peace at last. Without Takemichi, Mikey's descent into evil is inevitable. When the two meet for the first time in a present timeline, Mikey despairingly asks why Takemichi left Toman and says that he "wanted him to stay like a big brother would." It's clear that Mikey views Takemichi with the same respect and admiration that he did with Shinichiro.

Ken Ryuguji
Mikey and Draken are best friends. Mikey affectionately dubs Draken "Kenchin". They have known each other since 5th grade. At the time, Mikey had already made a name for himself as a fearsome fighter while Draken was a gopher for some older kids. Mikey encountered Draken when he was tasked to retrieve Mikey upon the older kids' orders. Mikey gets a good first impression of Draken and agrees to go with him to see the older kids. Mikey then easily knocks out the leader of those kids, and invites Draken to be friends with him instead, to which the latter agrees happily. From then on, those two became inseparable. The two have been shown to get into many pointless arguments, but always make up. Sometimes they even forget what they were fighting about to begin with. Mikey is the more fun-loving of the two, while Draken is the more realistic individual. When Pah-chin gets arrested, Draken is able to reason, albeit with the help and intervention of Takemichi, with Mikey about Pah-chin's sacrificial yet correct choice. The two are extremely close. The first time Mikey is shown crying in the series is for Draken when he survived being stabbed.

Keisuke Baji
Baji is Mikey's oldest friend. They had known each other since they were younger and even trained at the same dojo which is owned by Mikey’s grandfather. The two often joked around, even coming up with foreign names together to copy Emma’s. When Baji transfers to Valhalla, Mikey tasks Takemichi with "saving him" and bringing him back to Toman. Mikey says that if he fails to do complete his request, he will kill Takemichi. Mikey cares for Baji deeply to the point of punching Hanemiya Kazutora to death after he killed Baji in an alternate timeline. Mikey cried when Baji passed after the conflict with Valhalla.

Kazutora Hanemiya
Mikey and Kazutora were close friends. Even when Kazutora vowed to kill Mikey, Mikey still wanted to forgive him. However, when it became apparent that Kazutora was beyond the point of return and showed no remorse for destroying his life, Mikey mercilessly beat him to death in the original timeline. This was only prevented when Baji's charm fell out of Takemichi's pocket in the time leap timeline. After realizing Baji's sacrifice and his plea for his friends to stop fighting, Mikey once again forgives Kazutora, and Kazutora in turn realizes his delusions and repents for it. From then on, Mikey gains Kazutora's absolute loyalty.

Haruki Hayashida
Mikey is a great friend of Haruki Hayashida, so much so that he wants him released from prison after he stabbed Osanai.