Syan and Guest are a married couple of yōkai from the race known as Nāga.

Nāgas are giant snake yōkai that are either half-human, half-snake (human upper body, snake lower body) or entirely serpentine. Syan and Guest are both in their half-human, half-snake forms.

Nāgas in their full snake form possess a single horn in the center of their heads.

Characteristics of the Nāga Yōkai:

Low body temperature — They dislike cold places and prefer warmth.

Habit of coiling — They unconsciously coil their bodies, especially when relaxed.

Slit pupils — Their pupils narrow as their emotions intensify.

Scent detection via tongue — They can sense smells in the air with their tongues.

Molting — They shed their skin periodically; their skin is exceptionally sensitive immediately after shedding.

Snake-like fast reflexes.

Strong tail power — Used for gripping objects or pulling opponents.

Venom fangs — Usually hidden, revealed only when necessary.

Types of venom — Paralytic, hallucinogenic, and sedative.

Excellent night vision. Enjoy lounging lazily under the sunlight.

Nap near warm stones or fireplaces. Activity levels drop significantly when cold.

Prefer rainy days or humid environments. Primarily nest in caves.

Once a mate is chosen, they follow only that person for life. Once they memorize a mate's scent, they recognize it so strongly they cannot confuse it with any other.

Nāga yōkai recover quickly even when cut by blades and have the ability to spit venom. They are nocturnal, sleeping during the day and active at night. Their diet is carnivorous, and they swallow their food whole without chewing.

Syan and Guest are bonded partners who have imprinted on each other by plucking a scale from each other's lower bodies and swallowing them.