IBARAKI - A 29-year-old man accused of killing his pregnant former girlfriend, a nail artist in Mito, Ibaraki Prefecture, admitted the charges at his first trial on September 14, with prosecutors saying he used tracking tags to locate the woman after deciding he wanted to kill her and "reset" his life to before their relationship.
The killing occurred on New Year's Eve in 2025 at an apartment in Mito.
Haruka Komatsumoto, 31, was killed at her home after being struck in the head and stabbed in the neck.
Komatsumoto had married in July 2025 and was five months pregnant at the time of her death.
Takumi Ouchi, 29, a former boyfriend of Komatsumoto, was arrested on suspicion of murder three weeks after the killing.
At his first trial on September 14, prosecutors detailed the events they say led to the attack.
Ouchi began dating Komatsumoto in January 2024, but she told him she wanted to end the relationship around November that year.
Unable to accept the breakup, Ouchi repeatedly tried to contact her, but Komatsumoto rejected all of his attempts, prosecutors said.
He also tried to reach her through acquaintances, but those efforts were unsuccessful.
Prosecutors said Ouchi eventually came to believe that by killing Komatsumoto, he could "go back to before the relationship and reset his life."
Five days before the killing, Ouchi bought a stuffed toy of a popular character and concealed a lost-item tracking tag inside it that could transmit location information.
He placed the stuffed toy in a cardboard box and left it outside the entrance of Komatsumoto's family home, disguising it as a prize that had been sent to the winner of a promotional contest.
The following day, Komatsumoto took the stuffed toy back to the apartment where she lived with her husband.
Using location data from the tracking tag, Ouchi then began spending time around Komatsumoto's home, prosecutors said.
On the day before the killing, he bought a hammer that would later be used as a weapon as well as a hat and other items for a disguise.
On the day of the attack, Ouchi allegedly attached another newly purchased tracking tag to the license plate of Komatsumoto's car using adhesive tape.
After using the device to determine her location, he waited until Komatsumoto returned home, then approached her apartment carrying a cardboard box while posing as a delivery worker.
When Komatsumoto opened the front door, prosecutors said Ouchi used the cardboard box to block her view before repeatedly striking her in the head with the hammer.
He then allegedly took a kitchen knife from inside the apartment and stabbed her in the neck.
Asked by the presiding judge whether there were any errors in the charges against him, Ouchi replied, "No."
The defense is not contesting the allegations but intends to argue over the appropriate sentence.
The court is scheduled to hand down its verdict on September 30.
Source: FNN
