I assume you're talking about the wiki guide, cause the pdf guide
does just straight up give you the answer if you want to be lazy, but even the wiki is still pretty clear on what you have to do:
Why are you playing a story heavy game if you're not gonna pay attention to the story

Depending on which part you're stuck on:
Check every option
Maybe replay some previous Happy scenes
Make sure you have your volume on
Check the spoiler in the reply to the other person if you want a hint on how to get a Happy scene