Ao

Izana & Kakucho encountered Mucho in the orphanage, (her mother kinda dissappeared for too long and CPS got involved), then Ran on the streets (because parents responsibility? we don't know her in TR) when the three snuck out. Izana thought they were temporary goons since Mucho got picked up by her mother, who probably was gonna run off again, and Ran moved due to her father's work transfer.

They met again in juveniles detention, encountering the rest of S62.

The girls in general don't react well to older figures. So it is weird for Ran and Mucho that Izana had that "hopeful phase" for family, talking about having an older sibling. But again since Izana is the ring leader, they never questioned her because they probably be beat up and they want her happy. Though it got more conflicting for them when Izana managed to be fostered by the Sanos, leaving it to Mucho to check on Kakucho regularly and Ran focusing on Rindou.

They definitely, 100%, no doubt about it, jumped and robbed people together. The designer purse Ran has? Stolen, (even if she could buy it). The leather jacket? Stolen from a biker. Crashed a car? Probably that too. The "you tried to solicit a minor" blackmail, especially how Mucho can easily pass as an adult? Probably put enough fire on Shinichiro's ass to get Izana and them actual mental help.

Izana notes the more family stuff she talks about, Ran and Mucho don't comment much besides praising her, so she eventually focuses on other aspects like delinquency. She is aware Mucho lives technically by herself and Ran seeks attention or thrills for growing up very apathetic in her home. That awkwardness is gone when they are much older and have their shit somewhat together.

Izana doesn't have a sweet tooth but still tags along when Ran and Mucho are on the hunt for sweet pastries. She later brings strawberry cake for mini Kakucho.

Both Izana and Mucho suck in smiling for photos because they look evil in them. Ran hates that whenever she tries to take pics, or when doing Purikura, so she is always fighting for her life with her camera when she sees a natural smile.

Izana often ditches her babysitting duties onto Ran and Mucho to spend time with Kakucho.

Ran stopped coming by after being called “forehead” by the children. Before that she only wanted to handle the “well behaved one” (Emma).

Mucho is now handling five kids, the Sanos, Baji, and the Akashis like a champ. The babysitting money she manages to squeeze out of Shinichiro and Takeomi is usually spent on taking Kakucho for ice cream.

Whenever Ran wears heels, there is 100% guarantee at max one hour, she wants to be carried and that's somehow Mucho’s responsibility. Izana sees it as weak to be carried due to heels and hides her blisters with tape.

Izana refused any visits from them when she finally stayed with the Sanos because she realised she hyped up Shinichiro too much when she was much younger, and now trying to avoid revealing he is a “loser”. Teenager behaviour.

Ran is only disappointed that he isn't some “hot dude” when seeing him. Mucho remained hostile until she noted how the kids behave around him. Now all he gets is silent emotional blackmail from her, whenever he thinks he can sit down. And Izana isn't helping.

The three never went to the same school. But they somehow managed to hang out in the same spots regardless. Mucho is the quickest in finding them, then Ran and Izana doesn't have to, because they flock to her, but she will if they aren't quick enough.