i have a goldfish brain and i need help

Hi hello yall im looking for a yaoi manga where it looks like a 4p but its not, all of them are childhood bestfriends, the main couple has a tsundere mc and a lowkey pining ml, the side couple got together through casual sex (one is a blonde/brunette, and the other has mid length hair)

The tops are brothers, the one who got paired with the mc is the younger one. aaaaaa what else uhh i remember the side couple arguing during a festival and making up in the beach. Also the main couple had a chapter where they did homework and things escalted afterwards

I know the plot but i cant fucking remember the title wtf