SpoilerAge 5000+
Mujina is one of the antagonists of SSSS.DYNAZENON and the sole female member of the Kaiju Eugenicists. She is a stoic woman who, by her own admission, has no goal in life she's working towards, a stance emphasized in her discussions with her fellow Kaiju Eugenicists where she says she'll do whatever they decide on. The lack of motivation for a worthwhile goal is something she shares with Koyomi as discovered through their amicable conversation together leading to her briefly considered to live a better life than the one she currently has.
