Salam. In Japanese culture, it’s normal to bow down to someone out of respect. As a Muslim surrounded by Japanese society, most of the times I did this too, but then u know, the feeling of guilt triggered. I know in Islam we’re ordered not to bow down to anyone other than Allah. How to deal with this?
Alaikumassalam wa rahmatullah,
The only hadith we have that prohibits bowing when greeting others is found in al-Tirmidhi, Ibn Maja and the Musnad, but it comes through Hanzala b. Abdullah who is considered weak by many scholars. So there is no strong prohibition on bowing. Shaykh Faysal Mawlawi (from the European Fatwa and Research Council) permits bowing in sports like Judo as long as it is merely a form of greeting / showing respect.
References
Fatwa from IslamOnline that mentions Shaykh Faysal's opinion (Arabic PDF)