So Miyako and Touka's moms were friends.. Miyako's mom knew they were gonna get killed so...

So Miyako and Touka's moms were friends..
Miyako's mom knew they were gonna get killed so she asked Touka's mom to at least save her child, Miyako.. Touka's mom did just that and took Miyako to the Oosuka Family.. since they're a fairly strong yakuza family.. Miyako can be kept safe..

So here's the catch.. Miyako's DAD is part of that chinese gang.. thats been after Miyako for 8 years now. He prolly knew this was gonna happen.. thankfully, his mafia member of a wife had a better head on her shoulders.. and she managed to have her friend save her son.

I think what the chinese gang were doing.. is something psychological.. so Miyako will grow up broken, twisted and become a ruthless murderer. They want an unfeeling killing machine. They most likely killed the parents and blamed the 8 yr old Miyako for the crime.. so the kid would be traumatized.. and manipulate the child into doing whatever they ask him to. Coz.. if ur mind is in disarray, u lose rational thought, and u get easily manipulated and stuff..

They prolly didnt expect the Oosuka family to get involved tho.

Since the whole scheme of these chinese gang didnt happen coz Touka's mom took Miyako and hid him in their yakuza family.. they had no choice but become "guests" instead.. that way they can legally enter the family without being sent away. When can they force themselves in as "guests" if the Oosuka family is aware of them as enemies tho? Of course.. its on a special celebration open to all that Miyako would deff be present..
(〜￣△￣)〜

The Family head's birthday and his wife's prolly dont have to be celebrate so formally or openly, so they cant barge in.. or Miyako dont have to attend them personally coz he doesnt really have a significant rank in the family yet.. so those dont count.. but Touka's birthday.. Miyako will be present for sure.. and its a big celebration that gangs, yakuza, politicians etc will attend.. so since nobody really wants an open war between chinese gang and japanese yakuza.. in big celebrations like that.. these people can blend in and avoid being sent away, for formality ig.. even if they're unwanted guests.. the gang and the yakuza keep their peace on the surface.. but really, the Oosuka family wanna off these chinese gangster if they could so they can help Miyako.. but yknow.. modern times call for modern rules.

So i guess thats why on every birthday Touka have.. these guests go in and mess with Miyako's mind again.. persistently trying to get him join their side.. Miyako keeps killing them every yr tho.. instead of capturing them and interrogating them to learn the truth and be freed from his trauma.. which we cant really blame the kid.. i'd skin those bald heads myself if this happened to me.

Anyways, fast forward.. so we have 8 chinese mfvckers.. and one of them come as guests every yr.. and Miyako kills one of them every yr.. were down to the 8th and the last one.. Miyako managed to capture them alive and gave the half dead fvcker to Oosuka family for interrogation.. symbolizing him prolly finally being free from that trauma. I think.. the reason why Miyako would die if he didnt manage to learn the truth.. means that he would become dangerous to keep as family if he becomes mentally unstable and might have the tendencies to just randomly kill people or be violent.. THAT or he either goes down the depression path and eventually suicides.. so yea.. good for him that the *power of love* also gave him the will power to overcome (๑•ㅂ•)و✧

If yall ask y Oosuka family didnt just protecc Miyako like they do to Touka.. i think its the mindset of the family head that caused it to be that way.. we have Oosuka enemies that want Touka dead so the family loses their heir.. so yea.. Touka is lucky to still be alive.. so maybe, Touka's dad took that as an opportunity to train Miyako and have him guard Touka so he grows up experienced and fully able to protecc himself agaisnt the chinese gangsters.. they cant really coodle Miyako as he's being wanted by a big gang and he isnt really part of lineage.. the threat he brings technically dont weigh more that what he can offer, basically.. he's a capable kid.. but nothing more than that.. with the type of organization the family has.. protecting someone and risking the lives of their members just because of a child with no relation to them will just cause internal conflict in the group.. so the family head cant really be on hands on with that. He's helping in his own way ig. They're yakuzas afterall. If he cant protecc the kid upfront.. raise him up so he'll need no protection instead.. and Miyako grew up so well with that.

Hope this longass thing helped make stuff clear