TBHK Head Canon's

Things They'd Collect

Amane Yugi:

Amane would collect rocks from the gravel, only the shiny ones, or the ones that looked cool. He'd wash them off and keep them in a collection. (if one was plain enough, he would let Tsukasa have it to let him paint it, or do whatever).

Tsukasa Yugi:

Tsukasa would collect animal bones that he would find in the woods, or wherever. He would also collect stickers, especially the sparkly ones. (He would also put some of those stickers all over his door and walls, and put some on Amane while he slept).

Hanako:

Hanako collects things that people forget in the bathroom, but only the cool stuff. He would probably steal phones, and he'd go through them kind of quick cause he keeps dropping them in the toilet.

Nene Yashiro:

Nene would collect nail polish. She'd also make fake love letters to herself and keep them and show them off to Aoi, trying to brag. (she definitely would try to also collect her current crush's hair, like single strands of hair that might have fallen out).

Kou Minamoto:

Kou collects cook books and recipes of course. But he also collects photographs now too, deciding to try out what Mitsuba likes.

Mitsuba Sousuke:

Mitsuba collects photos he's made of course. Mistuba also collects flowers and puts them into a book and puts them in little plastic bag containers so that they don't die.

Sakura Nanamine:

Sakura would collect tea cups and different kinds of jewelry.

Natsuhiko Hyuuga:

Natsuhiko also collects different jewelry to his liking, but he keeps losing them, so he has to keep buying them.

That's all I could think of for now, I might update this later if anything else comes to mind.