Born in Hactan, Japan, Mika was a skilled child that learned how to use a weapon at a young age. She was somewhat mentally unstable in school, sometimes having homicidal thoughts about her classmates and teachers. She eventually(mostly)overcame this, however in-game it is still present in some situations.
Though Mika does not exactly "like" the weapon selection on the Islands, she will still use a Kaezer 10mm as her main weapon. She is first introduced to the player in the mission El Salvador, and makes a good first impression by immediately pointing her gun at Rico and Damon. In battle, she is very skilled with her weapon, and can sometimes pull a DJW Beret out of thin air and start dual wielding. This is even more impressive due to the fact that she is only 27. In the mission Se Revoltar!, after Marienfield gets shot, her mental insanity re-activates, and she starts killing everyone in sight not wearing Revolution colors. Mika secretly has feelings for Marienfield, which she does not like discussing, even though it is obvious to everyone besides him. However, at the end of the game she directly tells Marienfield, they kiss, and the game ends. Due to her being a JDM fangirl, and owning a customized Junsei Sokudo, Jack Harris visibly dislikes her. During the mission Destroy, Adrian Kaezer betrays the team by attacking Johnathan Castro and Mika. Johnathan gets away with minor bruises, however Mika is not as fortunate, being strucken and shot multiple times. She is healing for the next 5 missions until Se Revoltar. It is revealed in Bled For Days that she is part demon, but no explanation how is given in the base game.
Mika is one of the three people also in the Simulation along with Rico, the others being Jack and Johnathan Castro. She is met in the blast complex, and uses a AVCT SMG throughout her appearance. She sticks with the player until they reach the garage, where she hotwires a Old Van. She offers Rico a ride, but he insists on staying with Jack. She escapes by other means, however, as near the end her van is seen flipped and destroyed, however no body or weapon is found. This is confirmed, as when Jack is driving out with Rico, she waves to them in Johnathan's Red Canyon Pickup.
Apparently, before Rico came along, Jack and Mika were BF/GF, and they got along quite nicely. In 1989, it is revealed that she came to earth as a human-demon project, and Jack was the only person that felt sympathy for her past. It is unknown how they broke up, but it happened somewhere in a storyline gap. During TME, she is what about 39% of the missions are based around, and is seen in multiple random encounters. Jack does anything for her, and she does the same for him. During Harris's Last Stand, she is manning the Harringer H200 on top of the Jackson Spartan. After the battle is won, she climbs out and jumps onto Jack, they smile, Jack kisses her and the credits roll.
- 過剰殺戮 is Japanese for Overkill.