musasab (むささb) is the name used for his artwork, whereas hiiragi mu (柊むぅ) is the pen name he uses as author of light novel series Tensai Gekai ga Isekai de Yami Isha wo Hajimemashita.
https://www.pixiv.net/users/2079857
https://www.pixiv.net/stacc/musasab
https://twitter.com/musasab_HM
https://twitter.com/intent/user?user_id=2937045560
https://seiga.nicovideo.jp/user/illust/9506571
https://www.nicovideo.jp/user/9506571
https://pawoo.net/@musasab
https://pawoo.net/web/accounts/406359
https://sketch.pixiv.net/@musasab