Daikon is a variety (longipinnatus) of White Radish (Raphanus sativus).
Although the Daikon is highly popular in North Asia, it grows really well over a wide range of temperatures.
The plant has a striking appearance, with the large root growing partially above ground. Often 1/3 of the root is above ground, but it can be up to 2/3 of the root visible as it grows.
As is often the case with large seed, germination is highly reliable. You can plant single seeds and there is no need to thin like you would with carrots.
Daikon is very popular in soups, but is a versatile ingredient. It can be grated raw as a condiment. The leaves are edible and nutritious, though eating the leaves is not popular.
Also known as tillage radish the daikon is used as a cover crop, with the large roots breaking up the soil and decomposing in place.
For more details, see: https://en.wikipedia.org/wiki/Daikon