I'm the best thief in the business, not the most famous. I need to watch my step to keep it that way.
~ Kasumi Goto

Kasumi is a supporting protagonist in the original Mass Effect video game trilogy. She is a young Japanese woman who is believed to be the 'best thief in the universe' and certainly lives up to that theory, being able to steal many different things without a criminal record. Very few people have ever heard of her, and fewer can claim to have seen her in person. She is one of the two Mass Effect 2 squad members available only through DLC, the other being Zaeed Massani.

She is voiced by Kym Lane.


Kasumi thinks very highly of herself, being fully aware of her exceptional thieving skills; when asked by Shepard if opening Hock's extremely secure vault would be a problem, she simply reminds him/her that she's the best thief in the galaxy. True to her claims, Kasumi is exceptionally intelligent, being able to deduce all of the steps to take down the vault's defences in mere seconds. She is very careful and cautious, using a password and advertisement to contact Shepard instead of meeting him/her in person, in order to ensure it wasn't a trap. As she puts it, she's the best thief in the galaxy, not the most famous, and has to maintain a low profile in order to keep it that way

Despite her status as a thief, Kasumi is shown to have a kind heart; she rescued a child prodigy from slave-traders who planned to sell her on Omega, receiving a painting from her in return. She is also capable of showing respect for her enemies, listing multiple things she admires about Donovan Hock despite the fact that he killed her partner and lover, though she gets really angry when he speaks ill of him. She also admires the salarian Spectre Jondum Bau despite him trying to arrest her, saying that the galaxy need more Spectres like him, and even helps him stop an indoctrinated hanar diplomat from dooming his entire species, possibly at the cost of her own life.

An eternal optimist, Kasumi always assumes a situation could be worse e.g. when on a derelict Reaper filled with husks that's slowly crashing into a star, she's relieved that it isn't full of rats, However, she is horrified by the thought of children being experimented on, which is what was happening in the facility where Jack was once held. She also has a sentimental side, as shown by her desire to keep the files of Keiji's graybox in spite of the danger they could put her in. Her sentimentality is also shown by the fact that she used to leave red roses in place of whatever she took, not realising how silly and unproductive it was until she met Keiji.


Kasumi and her partner Keiji Okuda shared a very intimate relationship during their time together, always kissing and showing other forms of affection whenever they can. Kasumi, nicknamed "Little Bird" by Keiji, surprised him by decorating their Illium apartment in a romantic atmosphere, staying cloaked until Keiji found her by feeling the air. She rewarded him with a kiss and pushed him over to the bed strewn with petals, discussing Keiji's recent acquittal. Kasumi revealed her worry and covert presence at the trial, and she reiterated her desire to stay by his side.

Kasumi felt it was time to start anew and for Keiji to leave the "boring" Alliance, so Keiji shared with her his plan to steal from Donovan Hock on Bekenstein. She has never been to Bekenstein before, and easily persuaded she started to perform some of her tricks on Keiji in bed.

Less than a day later above Bekenstein, Kasumi led Keiji around the bowels of a ship looking for a good jump point out: an empty escape pod chute. She had the pod "repaired" back at Illium to account for any bookkeeping discrepancies. Keiji was beginning to have doubts on the heist, but Kasumi was confident on doing it. Arriving at the jump point, they kissed again before skydiving, using flight suits Kasumi tested on an earlier job at Sur'Kesh. Kasumi found the freefall vista beautiful, perfectly timing their chute release for a safe but stylish landing on their intended location. Keiji commented on his girlfriend's flashy stunt, who indicated that the show was meant for him before locking lips again against the skyline.

Kasumi cloaked and scouted ahead inside the building, counting six professional guards on patrol. She surmised that the expense of hiring the guards must mean that their objective is still inside, so she set about to distracting them while Keiji went on ahead.

The master thief extensively used her cloaking, martial skills, and a decoy program given to her by Keiji to thrash heavily-armored individuals unable to see where she's coming from. By the time they recovered, Kasumi was bidding them farewell as "she" (her decoy) locked a secure door between her and the guards. The real Kasumi and Keiji exchanged status updates, but hearing Keiji's abrupt scream made her panic and race toward his last known location.

The guards noticed her true whereabouts and resumed pursuit. Two of the guards caught up with her, only to be beaten with their own batons. Kasumi unlocked a door at the end of a hall at the third floor, only to see Keiji lying in a pool of his blood. She cradled the dying man in her arms and swore not to leave him, but guards were pounding behind the resealed door. Keiji beseeched his Little Bird to survive, and to retrieve his stolengraybox so they could be together again. Kasumi tearfully complied and left his body behind, activating her cloak and vowing to make good on her word.

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