What happens if you were catching a flight to Hawaii with your family on last call, and an unfortunate banana peel throws you uncontrollably rolling way off course and missing the flight all alone? Well, for Kat-chan he took a whole Wii U game's "story mode" protagonist for himself, trying to befriend the little critters (and no so little ones too) in a nearby street.
Big quotation marks around "story mode" because the only story bits are the opening sequence above, and an ending-plus-credits roll that comes at the very end.
Befriending street animals is easy (in the Taiko no Tatsujin universe at least). Go out (おでかけ) and take a stroll, and you have three animals to choose to impress. Play through the song to complete the goals, and the friendship gauge will fill. Maxing the friendship gauge and the animal will be visiting and staying to play with Kat-chan at the Wada household. There you can have Kat-chan sharing snacks (that costs some Kobans) to keep their happiness up (don't think too much into the snacks having chocolate in them and the pals containing not one but multiple dogs).
As expectable from previous games' plot-driven modes, the difficulty can be chosen from Easy (甘口) / Normal (中辛) / Hard (辛口). Not only does the higher difficulty means pulling in Muzukashii and Oni notecharts, there is also a chance that a challenge is attached with modifiers including Kimagure and Detarame, as well as the on-screen obstructions like in normal multiplayer play. They will be duly noted in the mission briefing though.
You can also buy items with Kobans to help with the appealing, like reducing goals or boosting gauge increments. And if you are so extremely graced with (say) Yuugen no Ran + Norudon 2000 + Puchipochi Onis and you are out of care to deal, you can just back out the streets and go back in again to shuffle the songs/goals.
And the ending? The (rest of the) Wada family returns home from Hawaii, surprised to find Kat-chan already home, and then they realize he was nowhere in sight in the whole trip. While Kat-chan copes with the non-existence of his presence, the family discovers the other surprise and scolds Kat-chan for the ruckus. That does not live long, as the presence of adorable little critters is so irresistible, everyone just lets it go and play with the animals. Cue smug Kat-chan getting out of a scolding, and roll credits for more antics with the animal friends.
