The story begins when high school student Kazuki Muto is killed one night saving a mysterious girl from a monster, only to wake up in his school dorm, believing it to have been a dream; however, he soon finds out that dream wasn't a dream at all when a giant serpentine monster attacks him and his sister. Tokiko Tsumura, the girl he saved, explains that the monster is a homunculus. Kazuki had been attacked and killed by it when he was rescuing her; however, she, feeling responsible for him, revived him by placing a Kakugane medallion in his chest, serving as a replacement heart.
| Title | Time | |
|---|---|---|
| 1 | A New Life | 2006-10-04 |
| 2 | The True Form Homunculus | 2006-10-11 |
| 3 | You've Become A Little Stronger | 2006-10-18 |
| 4 | Another New Life | 2006-10-25 |
| 5 | To Protect Someone | 2006-11-01 |
| 6 | The Butterfly of Black Death | 2006-11-08 |
| 7 | Whether or not You're a Hypocrite | 2006-11-15 |
| 8 | A Night in the Dorm | 2006-11-22 |
| 9 | The Hayasaka Twins | 2006-11-29 |
| 10 | It Seems We're Well Matched | 2006-12-06 |
| 11 | Till Death Do Us Part | 2006-12-13 |
| 12 | Carnival | 2006-12-20 |
| 13 | Signs Of Death | 2006-12-27 |
| 14 | Who Are You? | 2006-12-27 |
| 15 | An Intermediate Existence | 2007-01-10 |
| 16 | New Strength | 2007-01-17 |
| 17 | When Dawn Comes | 2007-01-24 |
| 18 | The Escape | 2007-01-31 |
| 19 | As Long As I Can Protect You | 2007-02-07 |
| 20 | With Strength And Spirit | 2007-02-14 |
| 21 | Gone Into Flame | 2007-02-21 |
| 22 | A Decision Is Required | 2007-02-28 |
| 23 | Boy Meets Battle Girl | 2007-03-07 |
| 24 | When You Die, I'll Die With You | 2007-03-14 |
| 25 | No One Could Ever Take His Place | 2007-03-21 |
| 26 | Period | 2007-03-28 |
