Named after a prominent early 20th-century playwright, author and translator, and presented annually by the Hakusuisha publishing house since 1955, the Kishida Kunio Drama Award is indisputably Japan's top honor for writers of plays premiered the year before.

As the same person can only win the accolade once, scooping a Kishida has also long been regarded as a rite of passage for ambitious young writers, with most winners being in their 20s.

Recently, however, the honor has gone to some later entrants to the contemporary theater world following careers in other fields — with this year posting the oldest-ever winner when 56-year-old Kenji Yamauchi's name came out of the Hakusuisha hat in February.

When we met recently in his Tokyo office and I asked him how he felt about becoming a Kishida record-breaker, the playwright and director — who founded his Shiroyagi no Kai (Castle Goat Party) theater company in the capital in 2004 — replied with a laugh, saying: "To be honest, I feel I am still a newcomer in the theater world, so I must work harder to develop my skills and seek out new approaches for my writing."

Nonetheless, his award-winning play, "Troisgros" (subtitled "Trois Grotesque") was hailed a real tour de force by audiences and critics alike when it premiered in November 2014 in Tokyo's artsy Shimokitazawa district.

Set during a rich middle-aged couple's home party, the play largely features men and women chatting in the back garden. However, after their polite introductions they soon show their true feelings as drinks flow and biting gossip and talk of sexual penchants takes over — much as works by Anton Chekhov (1860-1904), though generally set in mundane surroundings, subtly peel away appearances to portray the Russian master's views of humans' nature.

For his part, though, Yamauchi noted, "I think this type of play about mature people is now quite rare. Lots of deconstructed anti-theater is created by young dramatists groping for new, cutting-edge methods, but I'm interested in writing straight plays — though not beautifully planned ones with neat conclusions. I prefer just taking ordinary people's conversations in totally unexpected directions."

Although "Troisgros" was actually Yamauchi's 16th play since his debut piece for his company at the age of 45, his winning the Kishida award left many people wondering who on earth this aging "newcomer" was, where he'd sprung from — and why he started his theater career so late?

In fact, Yamauchi had been an award-winning director of CM (commercial message) films for the massive Dentsu advertising agency before turning freelance. It was him who had the clout to cast supermodel Naomi Campbell in adverts for the TBC beauty-salon company — and he also filmed the SoftBank mobile-phone firm's famed series of zany TV adverts starring the Shirato (White) family headed by Oto-san (Father), a big white talking dog.

After seeing a few plays in high school, Yamauchi said he became a regular theatergoer as a student at Waseda University in Tokyo — though he admitted that "working in theater wasn't among my career selections back then, as I knew it just didn't pay.

"But while I was a CM director in the 1980s and '90s, I worked with the scriptwriter and actor Toshifumi Muramatsu, and onetime, he asked me to write a skit for his solo performance, and after that I started writing full-length plays."

Then, when he finally switched from screens to the stage, Yamauchi abandoned the way he'd always plan every detail before going into a studio. Instead, he said he now normally starts writing a play without having its ending in his mind — or sometimes even its plot.

"First off, I appoint actors I'm interested in. I don't select them for roles I've already written, but I then write for the actors I've chosen," he explained.

"And rather than including particular themes or messages, I'd rather observe the actors' natures and build my play around imagining how they would react in the circumstances I set out.

"I think it's boring to see plays in which actors are used as role-players in the playwright's piece and could even be replaced by somebody else. I believe theater is primarily an art form in which to see actors themselves, so I far prefer plays in which they are vividly present on stage even though the story may have failed a bit."

For fans of Yamauchi both old and new, a chance to see those principles put into practice comes this week in Tokyo with the opening of his new play "Nakanaori Surutame ni Kudamonowo" ("Bringing Fruits to be Reconciled with Friends"), his first work since "Troisgros."

In contrast to that award-winning work which delved behind the public personas of well-heeled people, Yamauchi said this new piece piches such folk and poor lower-class people together and lets them go with the flow of their ensuing conversations and arguments.

For sure, audiences can look forward to displays of human nastiness and conniving but also to savoring some of the Yamauchi's hilariously poisonous and satirical way with words.

Indeed, he made no bones about saying, "In advertising, there are too many restrictions. If the client says don't show this or don't touch on some issue, we don't — whereas I have 120 per cent creative freedom in theater, and that's why I gradually moved to doing this."

Ah, the joys of live theater ...

"Nakanaori Surutame ni Kudamonowo" runs May 29-June 7 at Theater West, Tokyo Metropolitan Art Theatre in Ikebukuro. For details, call 03-3467-9422 or visit shiroyaginokai.com or www. geigeki.jp. Yamauchi's second indie movie, "Tomodachi no Papa ga Suki" ("I Love my Friend's Father"), will be released this winter by Geek Pictures.