Mikiraus has already teased what comes after v0.4.1. The roadmap includes v0.5 (adding a "Rival" character who competes for your waifu) and v0.6 (the introduction of a "New Game Plus" mode where you keep lifestyle skills).
New story segments have been added to provide deeper context for the primary characters, offering more variety in how their individual arcs unfold. Waifu Slut School -v0.4.1- By mikiraus