Will this love lead to happiness or despair?

Toruka is in a relationship with Iori, an ideal high-spec boyfriend who is the envy of everyone, and she is enjoying smooth sailing in both her private and public lives. One year into their relationship, Iori proposes marriage, asking Toruka to stay by his side for the rest of their lives. She is elated, but then she discovers that someone is stalking her. She enlists the help of her childhood friend Jin to find the culprit, but......? 24-hour surveillance, eavesdropping, tailing... a yandere man's warped love and obsession run amok in this dicey romance...!

(Source: K-Manga, translated)