The Alchemist Kamen Rider in an Anime Crossover

"Tendo-kun, you're playing the guitar wrong."

Tendo Tenko is an apparently ordinary high school student, until one day he receives a mysterious metal card. At the same time, his two childhood friends, the energetic airhead Yui Hirasawa and the socially anxious guitarist Hitori Gotoh, seem to have become caught up in some kind of strange incident.

Eerie "sound-wave monsters" begin appearing at school. They devour music and distort melodies, while strange musical-note marks appear on Yui and Hitori...

When Tenko puts on the belt and transforms into Kamen Rider Gotchard, he discovers that the outcome of this battle is somehow closely tied to the girls' music.

"We'll protect our everyday lives ourselves!"

"Hey, Tenko, after practice today... will you go get crepes with me?"

"T-Tenko-kun... I-I'll do my best..."

"Henshin!"

"We'll play today's BGM ourselves!"