Okazaki Tomoya is a student who goes to school only as a force of habit. He continues to be plagued by nightmares of a world with nothing left, where his existence is a mere conciousness. On the way to school one day, he meets a girl called Furukawa Nagisa, who from then on follows him to school every day, unable to climb the stairs by herself. While helping Nagisa to organize the Drama Club, Tomoya slowly starts to open up and actually enjoy his life again. But the dreams he has might be something more than just dreams..

[Source: Anime News Network]

Okazaki Tomoya is a third-year student at a high school somewhere in Japan, and does not take his studies seriously. Always late for class, he is seen as a delinquent by the rest of his classmates who are busy preparing for their college entrance examinations. Needless to say, he does not have too many close friends.

Tomoya does not seem to mind though — until one day he meets a girl, Furukawa Nagisa, who is left alone without friends at school because everybody she knew already graduated. "What a clumsy girl", he thinks at first. But talking to her feels natural and so, while helping her, he meets a few other girls from his school. Although he does not care much about them at first, he soon opens his heart as they get to know each other better.

[Source: AniDB]

In an alternate universe to the original Clannad anime, Okazaki Tomoya is dating Sakagami Tomoyo in the 24th and final episode of Clannad.

When Tomoyo is elected Student Council President, her dream to save the school's cherry blossom trees from being cut down begins to come to fruition. However, her never-ending duties and bad rumors about their relationship spread by fellow students due to Tomoya's reputation as a delinquent create a rift between the two. As Tomoya watches Tomoyo rise higher and higher into the distance, their relationship is stretched to the limit by a society that threatens to break them apart.

Life continues on for Okazaki Tomoya. A few months have passed since he confessed his love to Furukawa Nagisa. Now entering the second semester, he continues to meet a variety of different people, expanding his own world in the process. As well, Tomoya and Nagisa's relationship begins to enter a level of intimacy unlike before. Through his relationship with Nagisa, and his various encounters, Tomoya begins to understand the meaning and importance of family. Unfortunately, as Tomoya and Nagisa begin their own family together, they are faced with many hardships and challenges along the way.

[Source: Anime News Network]

――This is the story of a small miracle.
Stars from different universes and different times that were never meant to cross paths. By irony of fate, these stars come together in “Kaginado Academy”.
What awaits them there is a lively school life full of hope and dreams.
The wonderful encounters provide the stars with new radiance.
What awaits beyond that radiance...?

[Source: official website]