The Almadoren Arc is a time skip and will take place in v0.8 and will last for the rest of the game.
The Almadorens are the special forces of the Euclyca Corps. The highest ranking in fact.
The Guardians Arc has ended and the Invasion Arc will begin in v0.5, coming soon!
The Invasion Arc will last until v0.7. By that time the platonic quests will be in the game so you can get to know the characters of your choice on a more emotional level without the sexual interactions. The reward is a character crystal that can be traded in for an ultimate weapon. All 100 percent optional, but as you can see... the reward is kinda tempting~
Look forward to Mitsu coming during the Invasion Arc!