Shinji Kagawa wasn't the only Manchester United player to endure a relatively disappointing season under David Moyes, but few could have been looking forward to the end of a dismal campaign and a link-up with their national side as much as the Japanese star.

The former Borussia Dortmund man is idolised in his homeland. Rarely, if ever, did a press conference at a United game passing last term without at least one question from a Japanese journalist questioning Kagawa's absence or misuse.

Escaping into World Cup preparations must have been even easier given Japan's current form. Qualification for Brazil was sealed routinely by Alberto Zaccheroni's men, topping Asia's Group B with relative ease and recording five straight friendly victories on the bounce.

Ahead of Sunday morning's Group C opener with Ivory Coast, we spoke to Greg Double, an expert on the Samurai Blue, about Japan's hopes for the World Cup and Kagawa's current plight.

Qualification seemed to go without a hitch for Japan thanks to five wins from eight, with just the one defeat. What expectations are currently surrounding the team ahead of the tournament?

The term "Dark Horse" is overused in football but is, for once, rightfully applied to Japan. When it comes to expectations, the rhetoric from the players has been surprisingly strong. Though the intricacies of the Japanese language means that misquoting is more commonplace than with other nations, AC Milan's Keisuke Honda has been reported as saying that Japan can win the World Cup. Even the most ardent of "Samurai Blue" followers will admit this is a touch fantastical but it sums up the fan culture of Japan. They will back their boys as world beaters until they get beat.

How realistic do you think passage to the last 16 is for Japan? They're certainly a part of one the less powerful groups with Greece, Colombia and Ivory Coast.

It's certainly not out of the question, but you could say the same of any combination of teams in that group. Greece have all the glamour of a night out in Rochdale, but the same was true when they won Euro 2004. Even without Falcao, the likes of Jackson Martinez and Carlos Bacca mean the Colombian's are no mugs and, as long as someone remembers his birthday, Yaya Toure – along with Drogba and Kolo – could inspire the Ivorians to fulfil their "Golden Generation" billing.

The key for Japan is playing to their strengths. They won't out muscle the Ivory Coast, they won't out discipline the Greeks and they may not out speed the Colombians, but they've got enough attacking verve and dynamism to out class all of them. Whatever happens, they won't be dull.

Mainz's Shinji Okazaki nabbed eight goals in qualifying. Who, along with him, is worth keeping an eye out for in this side?

Keep an eye on Yoshito Okubo. The Kawasaki Frontale forward was arguably the biggest surprise inclusion in the Japan squad – having spent nearly two years in international wilderness as Alberto Zaccheroni tried almost every other man with a Japanese passport/accent in their traditional "problem area". He didn't quite make it in Europe with Wolfsburg, but has torn the J-League apart in recent seasons and forced Zaccheroni's hand.

How do you expect Alberto  Zaccheroni to set out his team in Brazil?

There are few things in football that are certain. The Germans will make the semi finals, England will go out on penalties, Japan will lineup in a 4-2-3-1 formation.

The bit that isn't so clear is which personnel will go where. The "3" is likely to be Honda, Kagawa and Okazaki – with Okubo my pick for the "1".

Sadly any combination of the "2" in midfield is lacking quality, as is the other "2" that forms the centre back pairing. However, Atsuto Uchida (Schalke 04) and Yuto Nagatomo (Inter Milan) are two full backs with European pedigree and are integral to Japan's attacking style. If fitness concerns surrounding both are overcome, this couple can boost the team's quality enough to make the last 16 a realistic ambition.

Shinji Kagawa endured a fairly rotten second season at United. What do you think contributed most to this?

There are so many factors. Firstly, the evolution of European formation means that 2 up front now looks antiquated. If Robin Van Persie is the "one", then Wayne Rooney drops into the hole. Juan Mata is proven Premier League quality, Adnan Januzaj one of the few bright sparks of a horrific season. Where does Shinji fit in a fully-fit United team? He seems ineffective out wide. I'd back Rooney AND Mata ahead of him in that textbook number 10 role – so he needs to be more of a threat operating slightly out of position.

It's easy to blame David Moyes, but when you're used to building a team around Tim Cahill and Leon Osman it's understandable that dealing with an enigmatic sort like Kagawa might be problematic. You only have to look at the coaching staff fiasco to know Moyes hated the unknown and even to the great Sir Alex, Kagawa was exactly that. He didn't stand a chance… but at least the "memes" and "free Shinji" campaigns produced a smile in an otherwise gutting season.

After his exploits in Dortmund, it's fair to say that Kagawa hasn't quite lived up to his billing at Old Trafford (yet). Do you think he'll eventually come good under Louis van Gaal or is it another case of a square peg in a round hole?

It does feel "square peg, round hole". When Sir Alex signed him it was because there was a perception that United's midfield lacked creativity. In the end, he was a bit part player in a team that won the league in a more traditional United way. Kagawa has never been fully understood at United.Under Van Gaal, I have no idea. Personally, I think it may well be more of the same – but even the hapless Tim Sherwood oversaw an impressive Adebayor renaissance, so what's stopping LVG doing the same for Shinji?

How does Kagawa typically perform for Japan?

Ironically, his biggest criticism at club level is his biggest strength for "Samurai Blue" – he's consistent. Honda is considered the more showy/Beckham-esque personality, Kagawa is Mr Dependable. He's got goals in him too, averaging over 1 in 3 for the international side.There's a real concern in Japan that Kagawa's perceived Ill-treatment at the hands of Moyes could impact his international showing. However, if his own tweets are anything to go by, "freed Shinji" is aiming to play with the sort of lucid liberalism the Old Trafford faithful have yet to fully see.

Just how important is he to Zaccheroni's plans?

He's the more reliable of two world class players in the squad, so vital. However, Japan are always going to be a sum of their parts and Kagawa needs to be a Cogawa (sorry) in a well oiled machine to be of most use to his boss. Whatever his Man Utd future may hold, a lot of people want to see him do well after this season.

The stocky striker is a poaching sort and got the winner in their 4-3 warm up victory against Zambia on the weekend. He'll either do nothing or score, a proper forward.