|Maison book girl|
- Koshouji Megumi (Founding member, leader)
- Yagawa Aoi (Founding member)
- Inoue Yui (Founding member)
- Wada Rin (Joined March 27th, 2015)
- Soumoto Kaori (Founding member, graduated March 27th, 2015)
On July 8th 2014, at BiS' disbandment live, Koshouji Megumi announced that she would be forming a new unit, Book House Girl, with former Izukoneko producer Sakurai Kenta. On November 5th, the group's name was changed to Maison book girl and Koshouji Megumi, Soumoto Kaori, Yagawa Aoi and Inoue Yui were revealed as the group's official lineup.
Maison book girl began performing live at the start of 2015, with the singles white and black being sold exclusively at their shows. On March 27th, Soumoto Kaori graduated from the group and Wada Rin joined the same day. In September their debut album Bath room was released.
In 2016, Maison book girl signed with Tokuma Japan Communications. They released their major debut, Summer continue, in March. In October 2016, Maison book girl toured Canada as part of the Next Music From Tokyo event. Their first nationally-distributed single River (cloudy irony) was released in November.
In early 2018 Maison book girl signed with the UK label Read The Air Records. Their first international release, Karma // bath room (UK Version) was released on vinyl on May 18th. To promote the single, Maison book girl held their first UK tour, performing at 4 different locations. Their third album, yume, was released on November 21st.
In early January, Maison book girl announced the release of their best-of album, Fiction.
- [2019.11.27-2019.12.22] Pick Ups! -Maison book girl-
- The B-Sides to most of their singles are readings of poetry written by Koshouji Megumi.