Sweet Gem ⇔ Chocolate Vale Tudo - S1.E12

Part A: It's valentine's day and the girls decide to make some chocolates, at school Tsumiki forgot the chocolates she wanted to give to Io. Everybody was having fun trading chocolates except Tsumiki. After school, Tsumiki runs back to her house to get the chocolate, but on the way back the chocolates got wet and then Io arrives with his umbrella to protect Tsumiki from the rain. Even when the chocolates were all wet, Io still accepted the chocolates.

Part B: It's White Day and the boys (inclusive Kyoya) decide to make chocolate marshmallow, white chocolate cookies and gem sweets as return for the chocolates at valentine's day. Sakaki has secretly made some pig feet marshmallows as revenge for Mayoi's frog-flesh chocolate (episode 2, but it backfires before the end). At the end Io and Tsumiki talked about the kittyface on Tsumiki's gem sweetbox that Io has specially made for her.