According to the director, young Japanese nowadays often have no idea what they want to achieve. "While the previous generations might work hard to buy a car and a house, young people today don't care much about money. It's their mentality that I wanted to capture in my films. I've always hoped to show the ray of hope that exists for people who are leading a seemingly purposeless life."

But the times have changed - for Ishii at least. At age 31, the director is a fully established member of the commercial film business.

His 2013 movie, , made him the youngest-ever director of a Japanese nominee for the best foreign language film Oscar. The humanist drama about a dictionary compiler also won big at the 37th Japan Academy Prize, taking home the prizes for best picture, best director, best actor (for Ryuhei Matsuda) and best script, plus two technical awards.

The critical acclaim for that film hasn't completely earned him respect in the industry, Ishii says. "But my relatives - especially the grannies - were a different matter," he says with a laugh. "They've finally realised what an awesome job I've been doing as a filmmaker."

Beneath the bizarre humour that coloured his early titles, there's a strong focus on family that runs through his gradually transforming body of work. As Ishii moves away from oddball comedies into the realm of thoughtful dramas, the recurrent setting of a motherless family has also become increasingly obvious in his films.

While the maternal figure is noticeably absent in (2010) and (2011), - which screened at the Hong Kong Asia Film Festival and will go on general release here on Thursday - revolves around the struggle, both emotional and financial, of a family of four when the ailing middle-aged mother is given only a week to live.

"That's not a conscious arrangement," Ishii says, noting that is adapted from a novel, "although it has somehow turned out that way - maybe because I did grow up in a family like that. It feels natural to me."

Ishii's mother died when he was seven years old, and growing up in a male-only household shaped his perspective, he says. "I had only a father and an elder brother at home. When there are only men in a family, nobody says anything. I think the mother is the connection that pulls everyone together. Once my mother was gone, our home went silent and the mood became sombre."

When Ishii decided to make the film in 2011, he was taken by author Kazumasa Hayami's youthful and sensitive take on the subject of family, as well as the parallels between that story and his own.

The fact that he was approaching 30 then also played a part in his determination to make the film. "For the Japanese, men are considered middle-aged when they reach 30," he says. "That's why I really wanted to work on this project when I still had the heart of a young man - during the last days of my 20s. More and more I've been feeling that I have to accept and face adulthood."

Ishii did that in a way when he formed his own family in 2010 by marrying Hikari Mitsushima, the lead actress of . Professionally, he has been taking on big-budget productions following the success of . "My mentality has changed when it comes to filmmaking," he says.

"I think it's good to attract a larger audience; I want my films to be seen. The fact that I won those awards was evidence that many people have watched my film, and that makes me happy. I'm not putting too much hope on winning further awards, but I do know that I'm fortunate."

Whether Ishii will live up to his full potential remains to be seen, but there already are signs that he's taking every opportunity that comes his way.

His new-found ambition is clear in his latest film , a Japanese-Canadian co-production that made its world premiere at the Vancouver International Film Festival.

A lavish drama that charts the history of a legendary baseball team in the 1930s, the film is not just a departure from Ishii's quirky indie beginnings, but also his more recent, modestly scaled commercial films as well.

"I realised it's a big change for me to go from doing family dramas to a large-scale historical drama. I'm treating it as a discovery process," he says, adding that he is a "very confident person who doesn't worry about whether a project is small or big, indie or commercial".

At the rate he's going, his career is likely to take even more twists and turns. "When I started I just wanted to make it as a director - and I did wonder whether this could develop into a long-term job that pays the bills," Ishii says. "I knew I must keep working hard to stay in this profession. I'm aware of the risk of not making the grade."

It looks like he's doing just fine.

Our Family