Amagami

is a Japanese dating simulation game. It has four manga adaptions, Amagami: Sincerely Yours, Amagami: Precious Diary, Amagami: Love Goes On! and Amagami! as well as an anime adaption, Amagami SS.

Seiren (セイレン, Amagami) is a prequel series produced by Studio Gokumi.

Plot
Two years prior to the present events, Jun'ichi Tachibana had his heart broken when a girl stood him up on Christmas Eve. The trauma caused Jun'ichi to grow cautious of love and dislike Christmas. In his second year of high school, Jun'ichi encounters one of six girls, Haruka Morishima, Kaoru Tanamachi, Sae Nakata, Ai Nanasaki, Rihoko Sakurai, or Tsukasa Ayatsuji, around Christmas time, who change his attitude towards love.

The anime is divided into six four episode story arcs. Each of which focuses on one of the girls trying to become Jun'ichi's love interest.

Seiren
Shoichi Kamita is an ordinary high school boy, who is faced with the university entrance exam and worried about his future. This campus romantic comedy, "Seiren", which means honest in Japanese, depicts his pure relationship with three different heroines. Each story is the unique and mutual memory between him and the heroine

Official

 * Video game's official website
 * TBS's official website

Other Sources

 * Wikipedia
 * Anime News Network (Anime)
 * Anime News Network (Anime's sequel)
 * Anime News Network (Manga)

Other Wikis

 * amagamissplus - duplicate
 * amagami-ss - duplicate