first wearing of a kimono in the New Year
Refers to the first time one wears a new or special kimono at the start of the year, often associated with New Year's celebrations.
新年に初姿を見せるのが楽しみです。
I look forward to showing off my first kimono of the New Year.
Compound of 初 (hatsu, 'first') and 姿 (sugata, 'appearance, figure'), referring to the first appearance in a new kimono at the beginning of the year.