As with most games in this genre, they have set "Seasons" for release of the available characters in this department.
- Coincidence was the first release, setting the stage for characters and their applicable backgrounds to some degree. The characters Jung Hi, Leo and Sol are pulled into your contract. You learn that William is your butler and that Eater is your enemy.
- Fate is the actual romance of the characters Hi, Leo and Sol. Pretty busy also released the purchase of each romance if you choose to skip Coincidence.
- Destiny is unknown at this time (as of January 13, 2021) but has Jung Hi, Leo and Sol listed on the top.
At this current time no other options have been released to us, but wiki will be updated if needed!