I'm not sure what you mean by "TOBU4". This doesn't appear to be a common word, phrase, or widely recognized abbreviation. Could you please provide more context or clarify what you're asking about? Are you referring to:

1. A specific company or organization?

2. A product or model number?

3. A code or identifier of some kind?

4. Something else entirely?

If you can give me more information, I'll do my best to help you with your query.