|First Appearance||Shikigami no Shiro Nanayozuki Gensoukyoku|
|Role||Supporting Character, Antagonist|
|Voice Actor (JP)||Mamiko Noto (Nanayozuki Gensoukyoku, III)|
|Voice Actor (EN)||Valerie Hagar (III)|
Tsukiko has long pale violet hair, and similarly-colored eyes. She wears a collar with a golden key attached to it, a black kimono with lavender insides and large sleeves, golden shoulder pads with red ribbons, a large red band, and several belts and chains.
Tsukiko is a childhood friend of Kohtaro Kuga's, betrothed to him at an early age. She was adopted by Kohtaro's grandfather and lived with the Kugas and Roger Sasuke when they were younger. She has been bedridden in a hospital for many years. The depiction of her in Shikigami III is likely not her, but a recreation based on the dreams and thoughts of the Castle's visitors.
She also has a key role in Shikigami no Shiro Nanayozuki Gensoukyoku, released before the third Shikigami title, though she acts much colder here.
The final fight in Shikigami III is a thorough affair. Tsukiko has a total of four final forms. The fourth form takes the longest by far. It consists of a lengthy firefight with the exterior of what's best described as a massive living battleship, which resembles Tsukiko naked, attached to a large fetus with multiple eyes.
- Welcome to the Castle of Nightmares. I'm your greatest nightmare.
- Let reality crush you.
- Perverted much?
- Like Roger Sasuke, she wields a sword. This can possibly be her Shikigami, or the source of its power. However, when she transforms, the sword is no longer visible.
- She likes to claim herself as an older sister figure to Kohtaro despite him seeing her more as a younger sister.
|Protagonists||Kohtaro Kuga · Sayo Yuuki · Gennojo Hyuga · Fumiko Odette Van Stein (Chibi) · Kim Dae-jeong · Niigi Gorgeous Blue · Roger Sasuke · Emilio Stanburke · Batu Harai · Mihee Kim · Reika Kirishima · Nagino Ise · Munchausen · Tagami|
|Supporting Characters||Sazae · Greater Manekineko · Moonsong · Devourer · Strider|
|Antagonists||Aku Miyoko · Juu Fujishima · Aku Hiroshi · Aku Bauman · Shoujo · Arala Cran · Anolegos Dundeon · Ajo Brothers · Yukari Horiguchi · Shintaro Kuga · Shikou Mibuya · Freedom Wind · Kagachi · Tsukiko Johjima|