Asahi Serizawa is a 14-year-old girl standing 153 cm tall, radiating an inquisitive and energetic spirit. She constantly searches for intriguing things and rarely stays still. Her intense interests are often fleeting; she displays straightforward enthusiasm when engaged in something new but becomes easily bored once her initial curiosity fades. This pattern extends to her talent for learning quickly, though sustaining her focus depends entirely on maintaining her engagement.

A defining characteristic is her distinctive speech pattern, frequently adding the suffix "-ssu" to words. She maintains a generally genuine and innocent outlook, often seeking positive aspects in situations and people. Her observational skills are noted, supported by a good memory, and she is ambidextrous.

Within 283 Production, she performs as part of the unit Straylight alongside Fuyuko Mayuzumi and Mei Izumi. This unit focuses intensely on striving for perfect performances. Her involvement with Straylight places her within the broader activities of 283 Production's idols, including participation in events like the Wonder Idol Nova Grand Prix (WING) and the agency's live concerts.

She appears in the anime adaptation's second season, introduced alongside Straylight and noctchill as new units joining 283 Production. The season narrative highlights Straylight's pursuit of performance excellence and the resulting ripples affecting other units.

Her character is featured in merchandise, including figures depicting her in relaxed poses or wearing original costumes designed for specific collaborations. These figures capture her appearance and sometimes reference her speech quirks and personality traits like her curiosity and innocence.