Ryuu-kun no Psycho na Kyuuai: Oyome-san ni Shiteageru

Despite suffering constant harassment from her senior colleagues and the parents of her students, kindergarten teacher Hana lives a happy life with her son and caring husband. As the harassment persists, however, Hana feels that she may be reaching her breaking point. Around the same time, strange incidents begin to occur around her. Those who inflict harm on Hana are suddenly disappeared, and the culprit behind these incidents might just be her adorable student Ryuuichirou, who desires Hana's hand in marriage. Will Ryuuichirou's deranged love for his married teacher lead to tragedy?

(Source: Bunkasha, translated)