Artist is MtU
https://www.pixiv.net/member.php?id=688784
Tweets by MtU17830715
It is CG from the VN Kimihane: Kanojo to Kanojo no Koi Suru Ikkagetsu.
https://vndb.org/v16377
http://baseson.nexton-net.jp/baseson-light/kimihane
https://www.mangagamer.com/r18/detail.php?goods_type=1&product_code=1203
