17(Crossover)

This idea probably doesn't make much sense and I haven't watched/read one of the animes/mangas I had this idea for.

So, we don't really know much about the Itoshi family and that made me think what if the Itoshi brother's mother had a brother and said brother had kids who Rin was close to(because he needs someone like that in his life).

And for some reason when I was thinking who would fir well the role of Rin's cousins, the Abe siblings(Haruaki and Amaaki) came to my mind and my mind settled on them.

Rin had always been close to the Abe siblings whenever they visited but that didn't happen often since they lived a bit away and his parents didn't get well along with the rest of the Abe family.

But that cold night, the Abe siblings had decided to visit the Itoshis and were the ones to find a broken hearted Rin in the middle of the snow.

Amaaki was close to go and murder Sae after Rin told them what happened but Haruaki stopped him and reminded him that Rin was the most important thing now and not dealing with Sae.

The three grow closer then ever since then as it is the Abe siblings who help Rin through everything that happened(so he is a bit more open then he was in canon) and tried to always be there for all his games, etc.

So, when the Japan U-20 vs Blue Lock was to happen, Haruaki demanded the director to let him not teach that day as he wanted to be there for his cousins which lead to all yokais to be curious about this cousin that was mentioned constantly but they have never met(so field trip time).

I imagine Haruaki and Amaaki having this big flag they wave around that says Blue Lock or just Itoshi Rin to show their support and whenever Rin mark a gol, they shout the loudest but the best is at the end Rin sees a small person(Mame) approach him and point towards the stands were Haruaki and the rest are and approaches them to which Haruaki basically picks him up and hugs him before passing him to Amaaki as they congratulate him.

Everyone from Blue Lock and Japan U-20 expected Rin to glare at the Abe siblings or make a face but he had a small smile on his face and started talking to them and asking them about the others that came with them(yes, Rin can see yokais).

Anything else is up to the writer.