Manga in order: #1-Te Wo Tsunaide Sora Wo #2-Amayakana Toge #3-Aisansi Otoko #4-Vanilla Star - See more at: http://www.mangago.me/home/mangalist/68409/#sthash.WwgfOUTw.dpuf
This side doujishi takes place before Hydra 7 and 8.
Vanilla Star