what was this?
Not quite sure of the plot of this episode, but it was part two of a four part late night drama.
Series was called もうひとつの象の背中 / Mou Hitotsu no Zou no Senaka (On the Back of Another Elephant) and aired October 20, 2007. The episode was called "Girlfriend"
The show was based on a book by none other than AKB48 producer Yashushi Akimoto, and revolves around a 48 year old salary man who finds out he has a terminal disease, with only 6 months to live. He wants to revisit people from his life and communicate his true feelings with them.
Appearing with Haruna is actress 東海林愛美 / Megumi Shoji (or it might be Manami Shoji, characters of her first name can be read both ways) who may not be active anymore (links to her blog and talent agency all not working). She was in a Korean language pop group called Miso, which also had a Vietnamese member, but that group seemed to exist for only a short while in 2008
Here is their MV for the song 'Say It, Say It':
M.I.S.O MV Say It Say It {With thanks to NamTiff}