Walk into a Japan restaurant, and you’ll instantly hear “Irasshaimase!” upon arrival. At the new Harajuku Gyoza in Potts Point, this greeting is ramped up to rock-star levels.

The overloud cheers are quite something – the staff really amp it up and stretch out the catchcry, like it’s a break-out chorus at karaoke. It’s fun to walk into a room and encounter such high-pitched enthusiasm from strangers, and this is the zippy energy and mood that this izakaya taps into. (Although, the high-decibel welcome isn’t exactly for everyone – I saw one guy do a U-turn straight on hearing the rousing echoes of “Irasshaimase!” that signalled his entrance.)

While the name evokes the neon-charged brightness of Tokyo, Harajuku Gyoza originates from Brisbane. The first outpost opened in late 2011, with a menu that scored some help from Ryan Squires (of the highly acclaimed Esquire). Despite this fine-dining pedigree, this izakaya is really a shot of unbridled fun. Ultra-colourful plates line the walls as well as your table, and they feature eye-popping and iconic Japanese graphics: ninjas, Mount Fuji, cartoon creatures powered by soy-sauce-jetpacks, for instance. The lights hide cutesy, loud messages on their underside (“Hai!” and “Sip!) and the soundtrack rolls out an endless stream of feelgood tracks, whether it’s Sinatra, J-pop or jazz.

And the food is just as cheerful – you can overload on many types of gyoza. There’s prawn, duck, chicken, vegie – even a kimchi pork special – as well as dessert ones. Will’s favourite is the salted caramel (which comes with a highly necessary scoop of vanilla ice-cream to counter the ultra salty-sweetness), while mine is the apple gyoza (this little parcel of cinnamon-spiced fruit tastes exactly like a miniature apple pie). There’s a nutella banana dumpling, too. It’s one of the few crunchy pockets of dough that doesn’t call for you to freestyle your own dipping sauce from the condiments on offer. (The menu suggests a ratio of two parts soy sauce to one part vinegar, plus as much firepower as you can handle from the jar of chilli.)

If you overdo it and need to calm down that raging, lip-burning after-effect, there’s a stack of Japanese beers on offer, plus some sake, umeshu and iced green tea. Or you could try the cooling cucumber salad, which is dressed in a miso-sweet sauce, or the snap and crunch of a salad, filled with shreds of carrot, cabbage and other sesame-coated vegies. Other snacks include squares of pork belly kakuni so soft you could use them as insulation, crunchy wedges of eggplant tempura, chicken karaage, agedashi tofu and more.

And in case the Tokyo-referencing name isn’t enough, the restaurant still manages to channel Japan in expected ways. If you go to the bathroom, you’ll find one of those famously hi-tech toilets the country is so famous for – you know, the multi-function, button-rich models that are so sophisticated that David Chang refused to throw up in one during his ramen binge for Lucky Peach because he had too much respect for the gadgetry (he aimed for the alley instead).

When Harajuku Gyoza opened in Brisbane, it quickly attracted a reputation for its queues, and you can easily imagine the Sydney branch easily earning quite a fan base. You don’t need to spend any yen to have some fun in Japan; this is an entertaining way to teleport to Tokyo – right from that very first overeager welcome. “Irasshaimase!”

Harajuku Gyoza, 9-15 Bayswater Road, Potts Point NSW, harajukugyoza.com. Follow Harajuku Gyoza on Twitter and Facebook.