Notably, you can use the upgraded pizza oven to cook up the Ultimate Joke Pizza, which is Badtz-maru’s favorite gift to get. You’ll get dough for the oven from Retsuko after gifting her items (which surely you are doing everyday, right?) and you can upgrade the oven by befriending Retsuko further.

Looking for rubber in Hello Kitty Island Adventure? Rubber is one of the main resources in the game, but it’s devilishly well hidden. It’s important to learn what rubber looks like and where to farm it though, as you’ll need it for various crafting recipes and quest objectives. Without rubber, you can’t advance the storyline.

Sanrio characters aren't all peaceful and adorable, and Retsuko is a shining example of this. Sometimes known as Aggretusko, this newer Sanrio character has quite a temper, so it only makes sense that he is found on Mount Hothead in Hello Kitty Island Adventure.