[Student Visa] Advice/Experiences with “Gyomu Itaku” (Freelance) contracts during university breaks?

Hi everyone,

I am currently a student in Japan and recently received an offer to work as a tour guide for a travel agency. The contract is structured as a "Guide Outsourcing Basic Contract" (Gyomu Itaku / 業務委託) rather than a standard part-time employment contract.

I plan to do this work mainly during my official university breaks (spring/summer/winter), but I wanted to ask the community for general advice on how students usually manage this type of arrangement.

I’m looking for insights on the following:

1. Experience with Freelance Contracts:

Has anyone else worked under a freelance/outsourcing contract with the standard "Permission to engage in activity other than that permitted…" stamp? I want to make sure I am understanding the general rules correctly regarding whether this visa permission covers freelance work versus just direct employment.

1. Calculating Hours for Immigration Limits:

Since this contract pays a "daily allowance" per tour rather than an hourly wage, how do you typically track your hours to ensure you stay within the 28-hour limit (or 40 hours during official breaks)? Do you count travel time, or just the active guiding time?

1. Tax Filing vs. Sole Proprietorship:

For students doing freelance work on the side, is it common practice to file a "Sole Proprietorship" notification (Kojin Jigyo Nushi), or do most people just file a final tax return (Kakutei Shinkoku) if their income exceeds the tax-free threshold?

1. Record Keeping:

Since the company won't be tracking my hours for immigration compliance (as it’s not an employment relationship), does anyone have tips or best practices for keeping personal records of work hours in case immigration ever asks for proof?

Any shared experiences or general tips would be really helpful.

Thanks!