Same-themed manga about kid fighting female ninjas from japanese imageboard.

Kodomo Janaishi! | I'm Not a Little Kid!

A Former Girl Professional Wrestler Mom and Bullying Kid

[Hochidonmai (Donburako)] Kids Know-It-All-Know-It-All-Know-Who-Go-Na-Na-Kid-Stream ★ ★

(C99) [sagejoh (sage joh)] Mou Kodomo ja nain da yo? | I'm Not a Kid Anymore, You Know? [English] [Nisor]

[Yakisoba Pants (Hiiragi Popura, Grand Deer)] Yanmama o Gaki no Sugata ni Natte Fukushuu NTR | Revenge NTR of a Yanmama in the Form of a Kid [English] {Doujins.com}

Older woman & kid body swap

(C84) [Karasuma Pink Higashiiru (Karasuma Pink)] Niwa ni wa 2-wa Niwatori ga Iru (Kid Icarus) [English] [Yuuta's Blog]

[Hidemaru] Kodomo ni Natte Okashi Makuru yo! Ch. 5 | Become a Kid and Have Sex All the Time! Part 5 (COMIC MILF 2013-06 Vol.13) [English] [Sergio]

(C90) [Karasuma Pink Higashiiru (Karasuma Pink)] Delivery Angel Land (Kid Icarus) [English] {TheRobotsGhost}

(ShotaFes 3) [Pometeor (Enotou)] Shinyakuseisho (Kid Icarus: Uprising)