As of 0.12, and from here on spoilers for anyone reading, the only 2 charactrs with missable events are Hana and Tami. For Tami, if you reject her at the blind date thing and then again when she tries to confirm, you miss one event. For Hana, if you choose "forgive and forget" at the spa event, you'll miss pretty much all her events, except like 2. "I need someting from you" will eventually reasult in a more... dynamic relationship.
As for the other events, there's an in game guide that imo is pretty good at informing you without outright giving you the answer. Just click "toggle hints" on the events menu and turn them on. It's the same with all the characters. If you've already fulfilled all the requests for an event, explore a bit. Maybe they'll trigger on their own on a certain day of the week, or maybe a special interaction will appear that wasn't there before
Enjoy the game, good luck