One: Kagayaku Kisetsu e - True Stories
Genres: Hentai
Type: OVA, Episodes: 3
Aired: Nov 21, 2003 to May 28, 2004
Studio: Arms
Source: Visual novel
Rating: Rx - Hentai
Synopsis:
In 1998 winter, another world happens to come to existence in me, though I used to be a normal student. It is covering my ordinary life as the snow covers the ground. Until then, I haven't noticed, what has stayed unchanged in my daily life, the familiar scenes that have always been there, the warmth of the person whom I haven't noticed that I love her. 

They have existed to bind me in this world in order not to let me leave. 

It is the moment when I begin look for the bind and the significant person, for the first time. The time goes, and the sun gradually begins to shine the season. I wonder where I will be, and who will grip my hand.