Until the Lights Come Back (2005)

With his telescope fixed on Tokyo's snow-filled skies, 14-year-old Shota, sees a woman, Maiko, leap from the roof of a nearby hospital. Fortunately, she simply lands on the next rooftop but, seeing she's obviously distraught, Shota seeks to visit the hospital.
At the same facility, Saeki is visiting his dying father. Dad drops a double deathbed bombshell that not only was Saeki the product of an extramarital affair but also his supposedly dead mother is alive and living in Tokyo. Dad makes the confession because he wants to see his true love one more time before he croaks.
Saeki has marital problems of his own: In addition to his wife filling out divorce papers, his mistress, Misuzu, won't let go. She arranges to meet Saeki in their regular hotel, where Chinese bellboy Dong-dong is finishing his shift before catching a latenight flight to Shanghai to see his gf for Christmas.
Elsewhere, pregnant Reiko is confronted by the return of her former lover, Ginji, who's just been released from a six-year prison stretch.
Last but not least, lonely bar owner Shinichi waits in vain for an ex-lover who's married someone else. Shinichi's forlorn manner is observed by the adoring Nozomi, who manages a candle shop in the same alley.
When a crashing satellite shuts down the Tokyo electrical system, the darkness provides each of these Tokyo-ites an opportunity to reveal their innermost feelings.