Yosoji no Haru
Tsubomi Sakagami, who has been an office lady for 18 years without any outstanding skills or achievements, is suddenly sent to a trade exhibition on the day before her 40th birthday. The person who helps her with this unfamiliar job is Kohei Nakajima, the new star of the sales department, 12 years her junior. Tsubomi works overtime, and she finds herself going home alone late at night on her birthday. Feeling anxious about her future, Tsubomi can't help but shed a tear, but then Kohei catches up to her and tells Tsubomi that he loves her…. Tsubomi, who has always been the unwanted single woman, is now in her forties, and for the first time in her life, spring has come… Will it be too late?
(Source: Koisuru Soiree+, translated)
Note: Published in 24 chapters online and consolidated into 12 chapters for the tankoubon release.