ソーダパンチでコワモテおじさんを救ったショウマはまたしても１人になる。
孤独なショウマは心優しい老夫婦に人里離れた田舎道で拾われる。
亡くした息子に瓜二つのショウマを本当の息子のように可愛がる老夫婦と幸せな時間をしばらく過ごす。
しかし、仮面ライダーの存在が徐々に明るみに出たことで、
シータとジープにショウマの生存が気づかれてしまい、ついに両者が対峙することに…！
マシュマロの力でショウマは強敵に立ち向かう！
After saving the scary old man with soda punch, Shoma is left alone again. A lonely Shoma is picked up by a kind-hearted elderly couple on a remote country road. They spend some happy time with an elderly couple who love Shoma, who is exactly like their lost son, like his own son. However, as Kamen Rider's existence gradually comes to light, Sheeta and Jeep become aware of Shoma's survival, and the two finally confront each other...! With the power of marshmallow, Shoma faces off against a strong enemy!
