Hoshiiro no Okurimomo ('Star Colored Gift') by Rei Toma
Ai is afraid of change and what the future awaits for her and her childhood friends. It's the 1st oneshot among the three stories by Rei Toma. It's her usual trademark art, kisses and sweet short stories. But I found the first story too serious, the second so-so and third one the best. The title has a ps2 otome version of the same name too.