Japanese men struggle to grow facial hair due to genetics, cultural norms, diet, grooming habits, age, medical conditions, environmental factors, and historical significance. The clean-shaven look is preferred in Japanese culture and is considered more professional. However, in recent years, younger Japanese men have started to embrace facial hair and use beard growth products or undergo cosmetic procedures. Facial hair growth is not just limited to Japanese men but affects many ethnic groups around the world. Ultimately, it's up to individuals to decide what works best for them.