Ninja Awatemaru

(from ebookjapan):

Original source material for the popular TV anime "Hana no Pinyunpyunmaru"!

Awatemaru, an apprentice ninja at Kouga Elementary School, is always late and gets scolded by his teacher.

Just then, his rivals from Iga Elementary School attack, and all is not well!

Let the slapstick gag comedy of the little ninjas begin!