I don't want people who start off to hate if i spoil something for them so if you want then look lower in my comment.
For Shika's last H-Event you need to go to Hana's house in the morning after the Big Dude's and The Nekomata's (forgot her name) attack on your village, if i remember right but also you have hints that show you what to do to unlock those Events so check the Affection Board. If not then you don't have enough affection to unlock it, check the Affection Board if i'm wrong because i forgot i haven't played it for a while.