MiComet is a weapon in HoloCure: Save the Fans!. It can be obtained through a collab between Elite Lava Bucket and Psycho Axe. This weapon periodically hurls 3 meteors at random locations that deal high impact damage and also leave behind lava pools that deal continuous damage to enemies that step on them.
MiComet is the official unit name of Hoshimachi Suisei and Sakura Miko. It is a portmanteau of Miko and Comet (which is the direct translation of Suisei).[1]
The item description mentions business partners, which is a direct reference to a joke between Suisei and Miko when talking about their on-stream relationship. Miko and Suisei were originally brought together as a unit by Cover for events despite their lack of off-stream interaction, although their relationship did deepen over time[2]