High school freshman, Aoi Rio, has a secret that can't be told to anyone. He actually watches "Magical Girls" anime! On his way back home after secretly buying anime merchandise as usual, he saves a girl named Sumire who fell from the sky. Sumire is disheartened because she believes her powers are not good enough. After Aoi encourages her by explaining the value of Magical Girls, Sumire asks him to become her Magical Girl instructor!
男子高校生の蒼井莉央（あおい りお）には誰にも言えない秘密がある――
それは「魔法少女アニメ」を見ることだ。いつものように人知れずアニメグッズを買いに行った帰り、蒼井は空から落ちてきた少女・菫（すみれ）を救う。自分の力不足に弱気になっていた菫に魔法少女の尊さを説き、活を入れる蒼井。
すると菫は自らの指南役になってほしいと蒼井に頼み――？
隠れヲタDK×ひよっこ魔法少女のでこぼこ青春ストーリー!!