Manmaru The Ninja Penguin,[1] released in Japan as Ninpen Manmaru (忍ペンまん丸), is a Japanese manga series written and illustrated by Mikio Igarashi.

It was serialized in the Enix magazine Monthly Shōnen Gangan from 1995 to 1999.

"What surprised me" (ボクってまんまる, Bokutte Manmaru) by Yumi Adachi is the series' opening theme while "Kagayakeru Hoshi" (輝ける星, lit.

"Stars Shining") by Miho Komatsu is the series' ending theme.

In 1997, a 3D platform game based on Ninpen Manmaru was released in Japan for the Sega Saturn, developed by TamTam and published by Enix.