Ooh I actually love talking about Mikako's relationship w her family, so thank you for asking anon <3 She has 2 brothers--Manato and Morimasa. Mana is 4 years older while Mokkun(Morimasa) is only a year younger than her. They're really close each other growing up and even after she was pulled to Devildom, they occassionally meet up to catch up. They're both sorcerers and practice magic.

Mana is the cool older bro and he used to get them both in trouble when they're kids. When they got older, he's actually worried when he sees Mikako grew more independant and rely less on anyone else, so he watched from afar. When their parents passed, during her 1st year in uni, he didn;'t hesitate to work extra hard to provide for her and their brother. He gave her aids, financially and emotionally in a subtle way since he knew she's too prideful to ask for help. They bond over their love for fast cars and metal music and often go to music festivals together.

Mokkun secretly looks up to Mikako A LOT, and while he always gets on her angry side (he just loves messing with his big sis), he openly shows how much he cares about her, even not verbally. He's wary of the guys she dated before Mammon and usually will give them a rough time just to see if they deserve his sister. He felt guilty since when they're kids, he got sick frequently so their parents had to give extra attention to his needs, but she never resented him at all for that. He constantly checks up on Mikako, visits her in Devildom, and even included her in his vlogs (he's a very famous Deviltuber and Y!Tuber). He's scared of her temper though, often addressing her as onee-sama when she scolded him XD