For Indian migrants, Japan is not nearly as attractive as the US, Canada, Australia etc. Wages particularly in engineering/IT are comparatively low, working conditions are tough, the language is difficult, and Japanese society is known for being xenophobic. Politely so, for most part, but still: you might not get beaten up, but neither will you ever be accepted as Japanese.

It's no coincidence that the biggest groups of immigrants to Japan are the Chinese and Vietnamese, who have a leg up on the language (Chinese characters for the Chinese, obviously, but Vietnamese has a lot of Chinese loans shared with Japanese too) and blend in better in terms of physical appearance and culture.