noun which may take the genitive case particle 'no'
Used as a no-adjective to describe something bright, cheerful, or sunlit, often in product names, titles, or descriptive phrases.
サニーサイドの部屋は明るくて気持ちがいい。
A room on the sunny side is bright and pleasant.
このカフェはサニーな雰囲気で人気がある。
This café is popular for its sunny atmosphere.