Question: Summer Days is an erotic visual novel developed by 0verflow, released on June 23, 2006 for Windows and later ported as a DVD game and for the PlayStation Portable (PSP), It is the second installation of "School Days" line of series, succeeding the visual novel of the same name and preceding "Cross Days", a Japanese erotic visual novel developed by 0verflow, released on which date?

Context paragraphs:
Imouto Paradise 2: Imouto Paradise!  2: Onii-chan to Go nin no Imouto no Motto!  Ecchi Shimakuri na Mainichi (妹ぱらだいす！2 ～お兄ちゃんと5人の妹のも～っと！エッチしまくりな毎日～ ) is a Japanese erotic visual novel developed by Moonstone Cherry and released on May 31, 2013 for Windows PCs and later ported as a DVD TV game.  "Imouto Paradise!  2" is a sequel to the visual novel "Imouto Paradise! ", featuring a new cast of characters, but with a similar plot.  Both games depict incest.

Imouto Paradise!: Imouto Paradise!  Onii-chan to Go nin no Imouto no Ecchi Shimakuri na Mainichi (Japanese: 妹ぱらだいす!  〜お兄ちゃんと5人の妹のエッチしまくりな毎日〜 , Hepburn: Imōto Paradaisu!  〜Onii-chan to Go nin no Imouto no Ecchi Shimakuri na Mainichi〜 , which roughly translates as "Younger Sister Paradise!  Older Brother and Your Five Younger Sisters Dirty Spree Everyday") is a Japanese erotic visual novel developed and published by Moonstone Cherry.  "Imouto Paradise!"  was first released on January 28, 2011, playable on Windows as a PC game.  On July 29, 2011, M-Trix produced an Android version of "Imouto Paradise!" , and on September 29, 2011, the game was released as a DVDPG edition by Dennou Club.  An English language localization of the game will be released by MangaGamer in Europe on August 22, 2014.  On May 31, 2013, Moonstone Cherry released a sequel to the first visual novel called Imouto Paradise 2

Island Days: Island Days (アイランドデイズ , Airando Deizu ) is a tower defense visual novel video game developed by Klon in collaboration with 0verflow for the Nintendo 3DS.  It is a spin-off of 0verflow's "School Days" visual novel series, and was released in Japan on July 3, 2014.  The opening theme is "Paradise (Past Plus Parallel)" by Kyōko Aihara.

Kango Shicyauzo: Kango Shicyauzo (看護しちゃうぞ "Kango Shichauzo") is a Japanese erotic visual novel developed and published by Trabulance, released on March 2, 2001 for Windows.  "Kango Shicyauzo" was released by Trabulance as a DVD TV game on July 25, 2002, entitled "Kango Shichauzo Nanana Triangle".  Another DVDPG edition was released on September 26, 2002, this time entitled "Kango Shichauzo Maioka Wonderful".  It was localized in North America as I'm Gonna Nurse You by G-Collections.  The English version was released on June 24, 2003.  Since its second revision, both current Japanese and English versions have "Voice Plus!"  as an additional subtitle to denote the inclusion of original voice actresses recordings for characters in the game.

Kanojo x Kanojo x Kanojo: Kanojo x Kanojo x Kanojo: Sanshimai to no Dokidoki Kyōdō Seikatsu (彼女×彼女×彼女～三姉妹とのドキドキ共同生活～ ) is a Japanese erotic visual novel developed by Crossnet, and released for Windows PCs on May 30, 2008.  "Kanojo x Kanojo x Kanojo" was later released for the PlayStation Portable, and as a DVD TV game.  A sequel visual novel, titled "Kanojo x Kanojo x Kanojo Dokidoki Full Throttle!" , was released as a PC game for Windows on February 27, 2009, and later released as a PSP game and DVD TV game as well.  The story follows Shiki Haruomi, who begins living with three beautiful sisters after the volcano on his island erupts.

Summer Days: Summer Days (サマーデイズ , Samā Deizu ) is an erotic visual novel developed by 0verflow, released on June 23, 2006 for Windows and later ported as a DVD game and for the PlayStation Portable (PSP).  It is the second installation of "School Days" line of series, succeeding the visual novel of the same name and preceding "Cross Days".  Unlike the previous titles, that exist in the same continuity however, "Summer Days" is a spin-off of the original story retold from the perspective of Setsuna Kiyoura, a high school student out for summer vacation who finds herself attracted to Makoto Itou, a classmate and fellow patron of a restaurant she eventually comes to work at.  The game retains the anime-like presentation familiar to the franchise, requiring little interaction from users, engaging players through a nonlinear plot they are given opportunities to change, and concluding with an ending specific to the choices made during play.

School Days (visual novel): School Days (スクールデイズ , Sukūru Deizu ) is a Japanese visual novel developed by 0verflow, released on April 28, 2005 for Windows as an adult game.  It was later ported as a DVD game and for the PlayStation 2 (PS2) and PlayStation Portable (PSP).  The story, a dramatic slice-of-life, follows Makoto Ito, a high school student who becomes the ambivalent love-interest of several girls during his second term, and the effects this has on himself and his relationships with other characters.  Though the game requires little interaction from users, "School Days" engages the player through a plot that they are given opportunities to change the course of during play.  The game concludes with an ending specific to the outcome of the story, some of which became notorious for their graphic violence.

Otome wa Boku ni Koishiteru: Otome wa Boku ni Koishiteru (処女はお姉さまに恋してる , lit.  "The Maidens Are Falling in Love with Me") , commonly known as Otoboku (おとボク ) , is a Japanese adult visual novel developed by Caramel Box and released on January 28, 2005 playable on Windows PCs.  The game was later ported to the PlayStation 2 and PlayStation Portable (PSP) with the adult content removed.  The Windows version was released in English by MangaGamer in 2012.  The story follows the life of Mizuho Miyanokouji, an androgynous male high school student, who transfers into an all-girls school due to his grandfather's will.

To Heart: To Heart (トゥハート , Tu Hāto ) is a Japanese adult visual novel developed by Leaf and released on May 23, 1997 for Windows.  It was later ported to the PlayStation and given voice acting.  A second PC version, titled "To Heart PSE" was released containing the PlayStation version as well as bonus games.  "To Heart PSE" and the PlayStation version had the adult scenes removed.  "To Heart" is Leaf's fifth game, and the third and final title in the Leaf Visual Novel Series along with "Shizuku" and "Kizuato".  The gameplay in "To Heart" follows a plot line which offers pre-determined scenarios with courses of interaction, and focuses on the appeal of the eight female main characters.  A sequel of "To Heart", "To Heart 2", was released on December 28, 2004 directly to the PlayStation 2.  A special bundle of "To Heart 2" and a PS2 version of "To Heart" was released on the same day.  The original PC release of the visual novel was titled "To Heart", however the anime and the PSE versions later changed to "ToHeart" without any space between the words.  The English release of the anime uses the former format.

Cross Days: Cross Days (クロスデイズ , Kurosu Deizu ) is a Japanese erotic visual novel developed by 0verflow, released on March 19, 2010 for Windows and later ported as a DVD game and for the PlayStation Portable (PSP).  The story, a dramatic slice-of-life, follows the life of Yuuki Ashikaga, a high school student who becomes the ambivalent love-interest of two girls during his second term, and the effects this has on himself and his relationships with other characters.  Though the game requires little interaction from users, "Cross Days" engages the player through a nonlinear plot that they are given opportunities to change the course of during play.  The game is the third installation of the "School Days" line of series, succeeding "Summer Days".

Supporting paragraphs: Summer Days Cross Days
Answer: March 19, 2010