Hi, I'm sorry but there's currently no way to purchase the game. Itch.io blocked our payments in their latest NSFW purge (along with many other NSFW developers). We have no way of selling any of our games anymore because of this.
We're figuring out what to do, currently we uploaded our latest game on Patreon (https://www.patreon.com/cutepen), but honestly this whole thing feels like a complete stop to our development.