Kin Sushi is absolutely THE best sushi place in the Southern Finland - no there are actually two Kin Sushis, the one and the original in Järvenpää and the second one in Helsinki. And yes, they both are great!
The sushi buffet is delicious, beautiful...and fresh. There's always plenty of sushis to chooce from, even for a vegetarians. There's also hot dishes too, but the sushi is the main thing here, unlikely in the most other oriental/sushi buffets.
Service is always rapid and friendly - although sometimes waitresses don't speak Finnish nor English...The most (if not all) of the staff is Japanise.
At weekends it's better to have a recervation for lunch, or prepare to wait by the door before to find a table. It can be a little crowded, don't even think about to go there with a wheelchair, the space between tables is minimal.
However, in the evening it shouldn't be a problem because Järvenpää restaurant is on the ground floor and in Helsinki they have wheelchair ramp to get by the couple of steps down to the restaurant, and it isn't so crowded at the evening so it should be possible to rearrange the tables a littlebit.
The Helsinki restaurant is more beautiful, in Järvenpää it's more simple and cafeteria-like.More