Humans aren't consistent.

Japanese tend to be very superstitious. So they may not believe anything while carrying charms and saying prayers for good luck. Many believe in an afterlife while not believing in God. Those that don't still just do the shrine stuff as tradition.

Religion: This is a specific set of organized beliefs and practices, usually shared by a community or group. A religion is a unified system of beliefs and practices relative to sacred things, that is to. say, things set apart and forbidden – beliefs and practices which unite into one single moral community called a Church, Mosque, Temple or Synagogue.

Spirituality: Connotes an experience of connection to something larger than you; living everyday life in a reverent and sacred manner. Spirituality though, breaks free from the restrictions and rigid structure associated with traditional religion like going to a place of worship on a specific day and dietary restrictions on certain days or even permanently and typically involves volunteerism, social responsibility, optimism, contributing to society and not just through prayer, connectedness with others and love of self/reason to care for self.