In Season 9 of Hawaii Five-0, Adam reveals that Kono left him.
Grace Park, an American-Canadian actress, well known for her role as Officer Kono Kalakaua in the police procedural Hawaii Five-0.
Season 7 Finale
Kono Kalakaua left Hawaii for Carson City, Nevada, where she joined a multi-agency task force combating sex trafficking. Not much of Kono’s story is shown after that. Basically, Kono joining multi-agency task force combating sex trafficking is to prove that Kono is all-consumed with her work on Nevada and she is unlikely to return.
Season eight Episode – I Ka Wa Mua, I Ka Wa Ma Hope (The Future is in the Past) Danny dreams of the future and sees Kono is mother of Adam’s child. The character Adam, portrayed by Ian Anthony Dale was upgraded to a regular character in Season 8.
In the midway of Season nine, Adam returns to Hawaii and tells the team that he and Kono have broken up.