According to the Daily Mail, Japanese tabloid Shukan Bunshun backed its claims with several images, including a Halloween selfie of Nagano and Tanaka posing cheek-to-cheek, a photo of them holding hands, and shots allegedly showing Tanaka leaving Nagano’s apartment after a night out drinking.

Both Nagano and Tanaka have denied the allegations. Kim and Nagano’s agencies have also dismissed speculation about their relationship, stating that the two are “just close colleagues.”

South Korean actor Kim Mu Jun. Photo from Kim’s Instagram

“There is no truth to any romantic involvement,” Nagano’s agency said in a statement. “However, we have sternly conveyed to Mei Nagano that her actions could easily lead to misunderstandings.”

The controversy has caused a stir on Japanese social media, with many fans expressing disappointment over what they see as a betrayal of Nagano’s previously “clean” public image. A major fan account dedicated to the actress has shut down following the allegations.

Despite the scandal, Nagano remains professionally active. Her upcoming film “Kakukaku Shikajika” is scheduled to premiere in May, and she is set to star in a big-budget historical drama of the same name, expected to release in 2026.

Japanese actor Kei Tanaka. Photo from Instagram/kentaaminaka_portrait

Nagano made her acting debut in the 2009 film “Hard Revenge Milly: Bloody Battle” and has since become one of Japan’s most prominent young stars. She has earned three Japan Academy Film Award nominations—two for Best Actress and one for Best Supporting Actress—and currently endorses several luxury brands, including Prada and SK-II.

Tanaka, who debuted in 2002, is known internationally for his roles in “Godzilla: King of the Monsters,” “Godzilla vs. Kong,” and “The Lost City.”

Kim, 27, received the Best New Actor award at the 2023 MBC Drama Awards for his performance in “My Dearest.”

He met Nagano while co-starring with him in the 2025 drama “News Anchor.”