Hei no Naka no Biyōshitsu
Volume cover
塀の中の美容室
Manga
Written by	Mina Sakurai
Illustrated by	Marco Kohinata
Published by	Shogakukan
Magazine	Big Comic
Demographic	Seinen
Original run	March 25, 2020 – May 9, 2020
Volumes	1

Hei no Naka no Biyōshitsu (塀の中の美容室, "Beauty Salon in Prison"), also known as The Depth of the Sky, is a Japanese manga series written by Mina Sakurai and illustrated by Marco Kohinata. It is based on Sakurai's novel of the same title, published in 2018. The manga was serialized in Shogakukan's seinen manga magazine Big Comic from March to May 2020, with its chapters collected in a single tankōbon volumes.

Hei no Naka no Biyōshitsu is Mina Sakurai [ja] and illustrated by Marco Kohinata. It is based on Sakurai novel of the same title, published by Futabasha on September 13, 2018.^[1] The series ran in Shogakukan's seinen manga magazine Big Comic from March 25 to May 9, 2020.^[2][3] Shogakukan collected its five chapters in a single tankōbon volume, released on August 28, 2020.^[4][5]

Hei no Naka no Biyōshitsu received an Excellence Award at the 24th Japan Media Arts Festival in 2021.^[6]

• Wakabayashi, Rio (October 3, 2020). 女子受刑者が美容師を務める、刑務所の中の美容室。そこで描かれる、人間模様に感動必至. Da Vinci News (in Japanese).
• Wakabayashi, Rio (October 16, 2020). 「塀の中の美容室」桜井美奈さん、小日向まるこさんインタビュー 刑務所内で髪を切る受刑者と女性客の再生の物語. Good Life with Books (in Japanese). The Asahi Shimbun. Archived from the original on October 17, 2020.

• Hei no Naka no Biyōshitsu official website at Big Comic Bros (in Japanese)