He'd like to work 1, maybe two days pw from home.
There's no "reason" other than he has a long commute and it would improve the quality of his/family life. Our dcs are growing up so it's not because of caring responsibilities etc.
He generally manages his own workfkow and is responsible for sites all over the world so most of his "meetings" are by telephone of involve travel away from his base office. His boss is based in the same office but they don't work together much are are rarely in the office at the same time.
He works for a large multinational so no issues around the burden on small businesses.
I can't see any business reason for it to be declined - they'd get more productive hours out of him with no impact on his colleagues but,
It's a Japanese engineering company, few women (so no history of flexible working) and a culture of very long hours/presenteeism. WFH generally considered to be shirking.
So, should he apply or would just making the application work against him? What are his chances of success?