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.

The three Hello Kitty Island Adventure yellow power crystals are hard to find, but don’t give up; without the yellow crystals, you can’t advance the main questline and unlock the Lilypad Lagoon region. If you’re stuck, this guide will help you use the Compass Tool and locate the yellow crystals.

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.