1st Lieutenant Kellye Yamato, sometimes referred to as Kealani Kellye or just Kellye was portrayed by Kellye Nakahara. She appeared in at least 167 episodes of the series (full accounting has never been completed), more episodes than some main characters, such as Henry Blake and Trapper John. The character grew steadily from a background (often non-speaking) character beginning in the second season, culminating in the season 11 episode "Hey, Look Me Over", which was centered around the character. In listing her appearances, it is probably easier to list the episodes where she doesn't appear.
She debuts as an uncredited extra in the first episode of Season 2, Divided We Stand. Still an extra, but established as a recurring O.R. nurse, Hawkeye first addresses her as "Kelleye" in Carry On, Hawkeye. In her first credited appearance in Season 2's Hot Lips and Empty Arms she was billed as Nurse Yamato. This name was never used in dialogue, and only used in the credits of this one episode.
The character then took several detours, being billed as Nurse Able in A Full Rich Day, then later Nurse Baker and even Nurse Charlie before finally settling down as Nurse Kellye or often simply Kellye. In fact the full name "Kellye Yamato" never appeared on the credits so it is a compound made up from her first credited billing and the first name which her character finally settled down to. As late as Season 10 in The Birthday Girls, she was credited as Lieutenant Nakahara (the real last name of the actress), which raises the interesting question whether the character's last name should be Yamato or Nakahara.
The first name "Kealani" was never spoken on screen, but according to interviews with the actress, that was the first name used on set when referring to the character.
Kellye described herself as "part Chinese, part Hawaiian" in Life Time and speaks Japanese fluently, as revealed in Communication Breakdown. She had great pride in her Asian American heritage and frequently took umbrage at racial slurs leveled by Frank Burns and cultural slights exhibited by Major Winchester. Her family lives in Honolulu according to her statements in the final episode.