hi anon sorry i took 3 months to reply i didn't want to think. unfortunately i still don't want to think so this answer will be short sorry

(vaguely in order)
ichisaki: some time during middle school/main story because saki wants to check it off her list of things to do and ichika is hopelessly in love
honasaki: probably the first to kiss after whenever they confess. sakis like ok we're dating i get to kiss you now and honami is the one who lets her do it (side note i think honashiho would be disappointed but not surprised to know that ichisaki kissed in middle school LMAO)
shihosaki: almost definitely after honasaki
ichihona: a few days after they start dating honami absentmindedly leans over and kisses ichika and ichikas like ?!,@?#(@#,@(@, and honamis like oh sorry ive wanted to do that for a while it kinda came naturally. ichika blushes a lot
honashiho: honami asks nicely and shiho lets her do it
ichishiho: would take them forever tbh but i think ichika would be doing one of her patented Gay Monologues TM and shihos like i can't not kiss her

also im posting a fic vaguely related to this for polyneed week so look out for that ❤️ ok bye