I quite like the relationship they both have in canon :3 !!

Musashi (and the BIC along with him) seem to be some of the first real friends Mob makes and I just love seeing how supportive Musashi is towards Mob 🥺 He helps him out in his training, encouraging him to keep going so he (mob) can reach his workout goals. But I also quite love how he's ready to help him out outside of club activities, or how ready he is to risk his life to save Mob, like at the end of s3 when they all just ran out to go get him when they realised he wasn't with them. Ain't nothing can put itself between him and his cute kohai.

I like how supportive Musashi is, and I bet once Mob is more accustomed to it all he's also as supportive about everything as he is 🥰

and ship-wise, I think it's pretty cute and can be pretty fun to play around with >:3 I haven't explored it a lot myself outside of BIC/Mob content, but the time I rambled about it was fun and made me enjoy the ship more than I did before.