Tokyo District Court this week ruled in favour of a young pop idol’s right “to the pursuit of happiness”.

A 23-year-old female singer was sued for damages by her management company for a claim of 9.9 million yen (AUD $122, 579) for having a relationship with a fan, in violation of a “no dating” clause in her contract.

In 2012, the singer, whose name was not disclosed, signed a contract with the agency (name also withheld) which included the clause “if performers are found to be dating a fan, they will be sued for damages.”

Monday’s decision by presiding Judge Kotsuya Hara to throw out the case against the starlet marks a milestone victory for female performers in the country’s notoriously cut-throat pop industry.

"We have to admit that forbidding pop idols to date by claiming compensation for damage goes too far," Judge Hara said in his ruling, according to public broadcaster NHK.

“The enrichment of one’s life that comes from association with the opposite sex is covered under the right of self-determination.

“Association with the opposite sex is part of the pursuit of happiness. Even taking into account the unique circumstances of being an idol, prohibiting such associations is going too far.”

“No dating clauses” are a standard practice in the fiercely competitive Japanese pop scene where aspiring stars are frequently subject to a series of extreme demands by their management regarding their behavior.

AKB48's Haruka Shimada told to lose weight or graduate from the group Netizens have stepped up to defend the idol in the wake of her appearance on Fuji TV.

The reasoning behind the no dating clause is that the stars must stay single in order not to shatter the dreams of fans.

Another unnamed 17-year-old singer was last year ordered to pay 650,000 yen for violating the rule.

Probably the most famous example of this was the case of Minami Minegishi, member of the pop group AKB48 who shocked fans by shaving her head and then posting this tearful apology after violating her group’s dating ban to spend the night with her boyfriend.

"As a senior member of the group, it is my responsibility to be a role model for younger members," Minami said in the video.

"Everything I did is entirely my fault. I am so sorry.

"I don't believe just doing this means I can be forgiven for what I did, but the first thing I thought was that I don't want to quit AKB48."

Shaving one’s head can be a traditional act of contrition in Japan but for outsiders, the video, which quickly went viral with millions of shares, was somewhat extreme.

Fans also jumped to Minami’s defence at the time, saying that she is entitled to a private life – something that as a result of this week’s landmark ruling, the legal system now concurs with!