

Episode 13: “A Heart Unswaying on the Water's Surface... (Part 1)”
- 13 of 25
- June 28, 2007
- 24 min
- Aired
Contents
| Series | Darker than Black |
|---|---|
| Episode | 13 of 25 |
| Japanese | 前編) |
| Original air date | June 28, 2007 |
| Episode length | 24 min |
| Studio | Bones |
| Previous episode | Episode 12: “When One Takes Back What Was Lost Within the Wall... (Part 2)” |
| Next episode | Episode 14: “A Heart Unswaying on the Water's Surface... (Part 2)” |
| Streaming | Hulu |
“A Heart Unswaying on the Water's Surface... (Part 1)” is episode 13 of the anime Darker than Black. It first aired on June 28, 2007.
Summary
The summary below describes what happens in this episode.
Hei, Yin, and Mao come under attack from a group of Contractors. When Yin disappears, Hei and Mao search for her while trying to evade their pursuers. Yin’s former piano teacher also asks Kiko to locate her, creating a race between the two sides to find Yin first.
Characters in this episode
Music in this episode
- OP 1“Howling” — abingdon boys schoolAnimeThemes
- ED 1“Tsuki Akari” — Rie FuAnimeThemes
Where to watch
Streaming services that list Darker than Black. What you can watch depends on your country. Acino does not host any video; each link leads to the service's own page.
Episode guide
All 25 episodes → · 18 of 25 episodes have a summary
About the series

Darker than Black is a science-fiction action mystery set in a world transformed by mysterious Gates and the emergence of people with supernatural abilities. Its story combines covert missions, competing organizations, and questions surrounding the altered world, presenting its central conflict through both…
Read the article →References
- “Darker than Black”. Kitsu. Retrieved October 22, 2026.
- “Darker than Black: Kuro no Keiyakusha”. MyAnimeList. Retrieved October 27, 2026.
- “Darker than Black”. AnimeThemes. Retrieved October 23, 2026.
Episode titles and air dates come from Kitsu. The summary is written by Acino with AI assistance and checked so that it does not copy other sites.