I am glad this manga got a good happy ending...IRL similar situations don't get much happy endings compared to the ending of this manga sadly...
Riko for the assist and did what the adults should have fking done herself. Good on them for not saying anything to the adults/police (Never admit to anything unless you know it can help or you have no choice)...They can go fk themselves and figure out what happen themselves without questioning the kids considering that they failed badly when Riko asked for help the 1st time around. Hope the piece of Sh*t father gets to spends at least 10+ years in jail for his crimes...
Collin thankfully got some therapy or mental help for a few years before she came back to join the MC and Riko.