Hajimari Wa Naka Kara
https://myreadingmanga.info/michinoku-atami-hajimari-wa-naka-kara-jp/
Chou to Hana no Kankeisei
This is the prequel series, which hasn't yet been translated - https://www.amazon.co.jp/%E8%9D%B6%E3%81%A8%E8%9C%98%E8%9B%9B%E3%81%AE%E5%B7%A3%E3%80%90%E5%89%8D%E7%B7%A8%E3%80%91%E3%80%90%E7%9F%AD%E7%B7%A8%E3%80%91-%E8%9D%B6%E3%81%A8%E8%8A%B1%E3%81%AE%E9%96%A2%E4%BF%82%E6%80%A7%E3%80%90%E7%9F%AD%E7%B7%A8%E3%80%91-%EF%BD%81%EF%BD%8B%EF%BD%81%EF%BD%82%EF%BD%85%EF%BD%8B%EF%BD%8F-ebook/dp/B07BFVWWHS - https://www.amazon.co.jp/%E8%9D%B6%E3%81%A8%E8%9C%98%E8%9B%9B%E3%81%AE%E5%B7%A3%E3%80%90%E5%BE%8C%E7%B7%A8%E3%80%91%E3%80%90%E7%9F%AD%E7%B7%A8%E3%80%91-%E8%9D%B6%E3%81%A8%E8%8A%B1%E3%81%AE%E9%96%A2%E4%BF%82%E6%80%A7%E3%80%90%E7%9F%AD%E7%B7%A8%E3%80%91-%EF%BD%81%EF%BD%8B%EF%BD%81%EF%BD%82%EF%BD%85%EF%BD%8B%EF%BD%8F-ebook/dp/B07CG7JDTH/ref=pd_sim_351_1?_encoding=UTF8&pd_rd_i=B07CG7JDTH&pd_rd_r=fd761c78-92fc-11e8-a11c-11f06d043b58&pd_rd_w=pbtwm&pd_rd_wg=h0FC9&pf_rd_i=desktop-dp-sims&pf_rd_m=AN1VRQENFRJN5&pf_rd_p=7990452376513976631&pf_rd_r=N8X6T8XDR78PNNFBFYEY&pf_rd_s=desktop-dp-sims&pf_rd_t=40701&psc=1&refRID=N8X6T8XDR78PNNFBFYEY
Toubou Kinshi!