Koi x Kagi恋×カギ; 恋×カギ～この恋は、世界を変えるカギですか？～; 恋X钥匙; A Diary of Our Love's Beginning; An L Drawn for You; Key of Love; Koi x Kagi - Kono Koi wa, Sekai o Kaergu Kagi desu ka?; KOIKAGI; KoixKagi; Love Space is Endless

Hinako Midou’s parents died several years ago, leaving her alone. Since then she has been passed from relative to another. Now she finds herself about to move to another new home, with a child her own age called Hayami Subaru-chan. Volume one includes: ? Extra Story Arc Hinako and Subaru visit the park with the pets, where Hinako has an unexpected encounter with someone from her past, Shuuhei-kun... ? A Diary of Our Love’s Beginning Kamiya Sae loves Toono Chihiro-kun, but her confession doesn’t go well. What will happen after they decide to become friends? Volume two includes: ? At the Start ? Extra Edition ? An L Drawn for You ? Love Space Is Endless