Leto was a male Kwejian that lived on the planet Kwejian in the late 32nd century. He was Kyheem's son, and Cleveland Booker's nephew. Leto was born after Booker left Kwejian in 3174.
In 3189, Osyraa used the threat of starving the Kwejian people, including Leto, to force Kyheem to turn over Booker and Ryn. After the USS Discovery crew were able to force Osyraa away from the planet, Kyheem brought his son to visit Discovery and meet Michael Burnham. During the visit, Burnham offered to introduce Leto to Lieutenant Linus, whose lizard-like appearance captured Leto's attention, adding "you can peel off a piece of his face if you want," as Linus was currently molting. Burnham later noted to Booker, "your nephew is hilarious." (DIS: "The Sanctuary")
In 3190, Leto had his Ikhu Zhen ceremony at the World Root accompanied by his father and uncle Book. Shortly after, a binary black hole-anomaly passed through the Kwejian system, destroying Kwejian and its population. (DIS: "Kobayashi Maru")
Leto's death particularly traumatized Booker, who continued to have visions and flashbacks of him out of grief. (DIS: "Anomaly (DIS)")
After marrying Michael Burnham, Booker named their son after his nephew. (DIS: "Life, Itself")
Leto was played by Luca Doulgeris.