ofc it's on the duration of the chapter four. like you guys had to put into consideration that aizawa's girlfriend has just freaking died... so can you battle against a dead person and against a trauma? i don't think it won't be easy getting over a loved ones death and even if this is shouen ai, wishing for it is a bit too much. the ending definitely spells out that aizawa is open-minded and started to consider yuusuke. ATM ofc it's understandable that he is still grieving and i would question his sincerity and feelings if he would easily fall in love with yuusuke. That part where aizawa called yuusuke's name instead of michiru's is a big turning point for the two of them. and during the whole month that they don't see each other, aizawa seems to can't get him off his mind. that's a positive response and i definitely see a budding love relationship here, since that's definitely an accepting response at the end so it's the perfect time that michiru contentedly cross over since there is a sure happy ending.
WAH THIS IS NOT SHOUNEN-AI! ITS MORE LIKE SHOUJO HE JUST LOVE MICHIRU POOR YUUSKE..THERE THERE...