- "They're not going to save this place. I won't let them."
Tomiko was the daughter of an Assemblyman. Some time before the Incident, Tomiko's brother Kenji was killed - supposedly in an accident - while researching human genetic modification on LV-1201. To investigate his death, Tomiko took a summer internship on LV-1201. She claimed to have found proof that he was murdered.
She bribed Corporal Harrison into giving her a disc that she needs for information on her brother. She later helped Harrison and gave insightful tips. In the final Marine level "Savior", she sacrificed herself and blew up the FOP (Forward Operating Pods) in order to get rid of the events that happened on LV-1201.
She may have had a small affection for Harrison in the later levels.
- Tomiko can be spotted in her office at the beginning of the third Marine mission, "Betrayal" — after Stiles instructs the player how to reach the communication terminal, going down a different corridor than the one Stiles recommends will reveal her office. Her back is turned towards the player and the door won't open, but entering the room with noclip mode reveals that it is, in fact, Tomiko. Curiously, an e-mail on Stiles's computer refers to "unauthorized transmissions emanating from the Pods", most likely referring to Tomiko's activities just one corridor away.