Well, Zaregoto is a serie, that is, Zaregoto Series.
Bellow you can see the listing of the entire series' titles.

• Kubiki Cycle: Aoiro Savant to Zaregoto Dzukai
• Kubishime Romanticist: Ningen Shikkaku・Zerozaki Hitoshiki
• Kubitsuri Highschool: Zaregoto Dzukai to Deshi
• Psycho Logical (Up): Utsurigi Gaisuke no Zaregoto Goroshi
• Psycho Logical (Down): Hikaremono no Kouta
• Hitokui Magical: Satsuriku Kijutsu no Niounomiya Kyoudai
• Nekosogi Radical (Up): Juusan Kaidan
• Nekosogi Radical (Middle): Akaki Seisai vs Daidai Naru Shu
• Nekosogi Radical (Down): Aoiro Savant to Zaregoto Dzukai