A 51-year-old man arrested on suspicion of stabbing a young woman to death in Tokyo’s Shinjuku Ward earlier this week had allegedly lent ¥18 million to the victim, investigative sources said Thursday.

Manabu Wakui was arrested Wednesday over the fatal stabbing of Toshino Hirasawa, 25, in front of her apartment. Wakui told investigators he had lent Hirasawa money on the assumption that they would get married, but she had not repaid the cash.

However, there is no evidence of the two ever being in a romantic relationship. The Shinjuku Police Station is investigating the murder as a possible one-sided obsession on the part of Wakui.