"Japan's sweetheart" actress Mei Nagano is facing a steep decline in her career as she struggles to cope with a claimed extramarital affair with married actor Kei Tanaka, which has had her dumped by endorsements, drama roles, and slammed by members of the public.

The scandal first broke in late April when Bunshun Weekly published images and alleged text messages suggesting a romantic relationship between Nagano and Tanaka, who is married with two children.

Despite denials from both parties—Tanaka claiming Nagano was "merely a junior colleague"—the backlash has been swift and unforgiving.

Since then, nine key brands, including global luxury names such as Prada and SK-II, have retracted ads featuring Nagano.

Marketing analysts say the move reflects a hardline stance from sponsors concerned about image association.

Once a top-10 advertising star of 2024, Nagano now faces a near-complete wipeout from commercial campaigns.

In addition to the loss of endorsements, Nagano has withdrawn from the lead role in NHK's highly anticipated 2026 drama, "Toyotomi Brothers!", a decision confirmed by her agency, Stardust Promotion. "Given the current situation, we have determined that it is best for Ms. Nagano to step back from upcoming projects," the agency said in a brief statement.

The fallout from the scandal extends beyond professional losses.

According to Yahoo Japan, sources close to the actress report that Nagano has become increasingly withdrawn and emotionally distressed, isolating herself at home and obsessively trying to identify the source of the photo leak. "She has become suspicious of those around her," one unnamed acquaintance said. "Her trust in people has been shaken."

Public opinion in Japan remains largely critical of the government. While scandals involving male celebrities have occasionally faded with time, female stars often face harsher and more enduring consequences.

Cultural commentators suggest Nagano may struggle to find leading roles until at least the end of 2026, if not longer.

Adding to the controversy, the Bunshun report also alleged a "closeness" between Nagano and a Korean actor who co-starred with her in the 2025 TBS drama Caster.

No further evidence has surfaced, but the implication has fueled gossip across entertainment circles in both Japan and South Korea.

Nagano, 25, rose to fame with roles in My Love Story!! And we made a Beautiful Bouquet, which became a symbol of innocence and charm to audiences across Asia.

Her clean-cut image made her a favorite among advertisers and drama producers alike—until now.

As of press time, neither Nagano nor Tanaka has issued a personal public statement beyond their agency's brief denials.

Legal action regarding the leak of private materials has not been confirmed.

For now, the once-beloved actress faces an uncertain future in an industry known for its rigid expectations and slow forgiveness.