Thatched roofs are traditional in Japan. Thatching was the usual roof material for farmhouses, and was also used in some high-status buildings, including temples and shrines.

Rice straw and, to a lesser extent, wheat straw, are/were used, but were considered inferior thatching materials. The two best-regarded thatching materials were (and still are) Miscanthus sinensis (Japanese pampas grass) and rushes (AFAIK, usually Juncus effusus (common rush), which is also used to make tatami omote, tatami mat covers). Some types of bamboo are used (small varieties), and cedar bark. Where bamboo is used, it is often used for corners on the roof, while the rest of the roof is thatched with a different material.

Pampas grass and rush thatching would typically last for 50-70 years, while straw thatching would last for up to 30 years. Modern thatching doesn't usually last as long as thatching used to in the past, since wood fires are used much less often for cooking and heating - the smoke rising from such fires would help preserve the thatch. With about 100,000 thatched buildings remaining in Japan, maintenance keeps about 300 thatchers working.

Japanese pampas grass, which usually grows about 1-2m tall:

• https://en.wikipedia.org/wiki/File:Miscanthus_sinensis_ja01.jpg

Common rush, which usually grows about 1.5m tall:

• https://commons.wikimedia.org/wiki/File:Juncus_effuses.jpg

Some Japanese thatched buildings:

• https://i.pinimg.com/564x/ec/7f/56/ec7f56f0f6fb26d1505cc5e7a4966ca4.jpg

• https://resources.matcha-jp.com/resize/720x2000/2017/06/09-28466.jpeg

• https://i.pinimg.com/originals/00/bf/81/00bf8112da17c0380bfc15b4a44ed83a.jpg

• https://www.youtube.com/watch?v=BRX6JGOk7H0

A roof being thatched:

• https://www.nist.gov/image/18el011thatched-roofhouseinjapanbernardgagnonccjpg

Tile and metal sheeting largely replaced thatch for new construction after WW2.