Shiranami no Illusion
A one-volume work containing 4 stories total, including the title work "Shiranami no Illusion"
[From Ivyscan]:
Ryo is a boy who loves flirting with girls. One day, he met a beautiful girl named Touko by the beach. Ryo is soon deeply attracted to Touko, but because of an incident where her fiance died in a tragic accident, Touko locked up her own heart. How is Ryo going to help Touko leave her sadness and pain?