Kento's Tanto is a compact knife of Japanese make, usually stored in an inline sheath that disguises its true nature until drawn. Because of this, it has a very high Concealment rating, allowing a heister to carry it into crowded locations without drawing much suspicion.
Statistically, it is similar to the blade wielded by Jiro, dealing exceptional damage per second. However, it trades some speed as well as a noticeable amount of range in exchange for higher Concealment and a faster charge time.
Due to the unorthodox design of the knife and the fact that Kento is a veteran Murkywater mercenary, it is likely a keepsake, either given to him by Jiro and his wife before the kidnapping, or by whomever raised him afterwards.