Misaki Aoyagi- Mother. Physically and mentally abusive to him, but he loves her anyway. He used to visit her frequently, but recently due to interference from a number of people he's cut off communication with her for his own safety. He still worries about her greatly and will call his father to make sure she's alright. Despite this, Ritsuka feels incredibly guilty for abandoning her. He won't admit that he feels he did this to his friends because he knows they'll worry, but he's been doing a lot better lately because he's away from her influence.
Mr. Aoyagi- Father. He's not around much and is mostly just a souce of income. He doesn't do anything to help Ritsuka or Misaki besides financial and usually just runs off on business trips. Ritsuka doesn't care for him much, but has been recently texting him solely for the purpose of making sure that his mother isn't doing too poorly during the brief times that Mr. Aoyagi comes home.
Seimei Aoyagi- Ritsuka's older brother and a huge influence on his life. Deceased(?) Ritsuka thinks he is anyway, despite a few suggestions that he may not be. Ritsuka's afraid of finding out if he is alive, because that would mean a number of complications and even more questions than he already has. He originally had set out to seek vengeance for Seimei's death with Soubi Agatsuma, but after Soubi's disappearance he's been left with no choice but to remain at PLC without answers.
Friends
Albel Nox- Best friend. Ritsuka had trouble getting along with Albel at first due to Albel's fairly violent tendencies, but they have an ability to understand each other on multiple levels. Ritsuka knows that Albel would do anything to keep him safe and also knows how to talk him out of doing those things as well as trusts that if he asks Albel not to do something, Albel will listen even if they both hate following other peoples' orders. They don't mind spending time together doing not much of anything and tend to just enjoy each others' company.
Kadaj Espere- They were close friends until Kadaj's attempt to attack Albel despite specifically promising Ritsuka he wouldn't. Ritsuka and Kadaj went through a rocky period after that but they're on the mend, though Ritsuka still has issues trusting him. They like playing video games together.
Zack Fair- Ritsuka thinks Zack is the nosiest person he knows, but because of Zack's continual pressing his nose into hsi business without permission, Ritsuka learned afterward that it was okay to trust him. Ritsuka does believe he's a good person, but wishes he would mind his own business a little more often.
Acquaintances
Lightning Farron- They're both in the media club, but haven't really talked much.
Ciel Phantomhive- Ritsuka likes Ciel. He thinks he's intelligent, even if they have their disagreements. He wouldn't mind getting to know Ciel more, but he gets the feeling Ciel probably wouldn't like that so he doesn't go out of his way to try.
Soma Asman Cadart- They've only really talked once. Soma thought he was a cat god. Ritsuka thought Soma was kind of an idiot and explained that he wasn't.
Other
Harumi Fujiyoshi- Ritsuka thinks she's strange, largely due to her frequent attempts to kidnap him and attempt to get him to dress up and make an appearance at TSABO. He's been kidnapped more than once, but managed to avoid having to meet her demands beyond the first few times. She stopped kidnapping him, but does follow him sometimes. Ritsuka thinks she's weird, but knows she's pretty harmless.
Ion Fair- They're not quite friends, but he's talked to Ion more than once and hears a bit about him from being Zack's friend.
Soubi Agatsuma- Ritsuka's known Soubi since he as 12, after Soubi showed up claiming to be his brother's friend and stealing his first kiss and claming he loved him. Soubi eventually actually loved him for reasons other than Seimei's orders and Ritsuka gradually began to return his affections. Around the age of 15 Ritsuka began to feel sexually active and after some experimentation agreed to give his ears up to Soubi. Soubi, however, disappeared without saying goodbye some time after.