Trying to get info and source of this plant but I do not really know whether proper name is Japanese, or Chinese, onions, they grow similarly to scallions except crop year round and can be used on a "cut and grow" basis.
Would appreciate any further details about them, whether seeds or bulbs and their cultivation in our climate.
Would these be what you are after
http://www.kitazawaseed.com/seeds_bunching_onion.html
DT Brown have a couple of varieties called Ishikura and Shimonita
http://www.dtbrownseeds.co.uk/acatalog/71_onion_seed_pickling_and_salad.html (http://www.dtbrownseeds.co.uk/acatalog/71_onion_seed_pickling_and_salad.html)
hiya, Kaido, welcome to the site, we've grown ishikura , they grow like a leek rather than an onion :)
The Kitazawa link is interesting but I suspect they won't ship outside the US - there is a reference to possible problems shipping to Canada.
There is another company in California that also do them but again they won't ship outside the US.
http://www.southernexposure.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=BONION
However, Roguelands, do one heirloom variety and they do ship outside the US
http://www.vegetableseed.net/heirloom-vegetable-seeds/onion-seeds/onion-seeds.html
Kaido, Pity you don't live in the Northeast you could have all you wanted. Not that you need many, i call them Russian onions as the have rushed all over my garden.
I have seen some of these seeds on offer from some of the companies I buy from in the US, not the company listed, it is a lost cause, I will fish out the catalogues and get back to you . PLEASE keep away from Roguelands.XX Jeannine
I do have Ishikuro which is marketed a spring onion but i ca be left in the ground and left to get as thick as a carrott, like a leek but more oniony.Very long ahrvesting period, sow once and they last a very long time
XX Jeannine