Hentai Manga like Kowaremono

Nudist Beach ni Shuugaku Ryokou de!!

Also known as The Nude Beach Field Trip!!.

Status: Finished
Genres: Hentai

Oh, to be on a nude beach with a harem of all your classmates! Another legendary story from Shiwasu no Okina, this title tells you exactly what you’re going to get!

Henshin

Also known as Metamorphosis.

Status: Finished
Genres: Drama , Hentai

Saki Yoshida is a graduating middle school student with little to look forward to in life. Having been shy at the beginning, she ended up not making a single friend during middle school and wants to change that in high school starting with her looks. Saki might find out that she got more than she bargained for, though, when fate takes a turn for the worse and her newly blooming youth crumbles.

Shuugaku Ryokou no Bus no Naka de

Status: Finished
Genres: Hentai

In the school bus she ends up sitting with a guy student. What will they do to pass time? Note: 7 Pages Short Story

Oretoku Shuugaku Ryokou

Status: Releasing
Genres: Hentai , Romance

Notes:
Originally serialized under the title Oretoku Shuugaku Ryokou: Otoko wa Josou Shita Ore dake!! (俺得修学旅行～男は女装した俺だけ！！).
The main story spans 29 chapters/66 episodes, and subsequent chapters/episodes are episodic, placing focus on a single female character.
Each chapter is split into 2–4 ‘episodes’ on mobile reading platforms.

Iya da to Ienai Jimikei Shoujo Shuugaku Ryokou Soushuuhen

Status: Finished
Genres: Hentai

Iya da to Ienai Jimikei Shoujo to Jishou Televi-kyoku no Otoko-tachi (イヤだと言えない地味系少女と自称テレビ局の男たち)
F Taku no Omakebon C92 (F宅のおまけ本C92)
Iya da to Ienai Jimikei Shoujo to Chikan Densha (イヤだと言えない地味系少女と痴漢電車)
Jimikei Shoujo to Love Hotel (地味系少女とラブホテル)
Iya da to Ienai Jimikei Shoujo to Konyoku Onsen (イヤだと言えない地味系少女と混浴温泉)
Konyoku Onsen after (混浴温泉after)
Iya da to Ienai Jimikei Shoujo to Hamabe no Gaikokujin Ryokoukyaku (イヤだと言えない地味系少女と浜辺の外国人旅行客)
F Taku no Omakebon C95 (F宅のおまけ本C95)
Iya da to Ienai Jimikei Shoujo to Kyoutou Sensei (イヤだと言えない地味系少女と教頭先生)