Like a Dragon: Ishin!

Paying off Haruka's debt will cost you a total of 100 ryo. Save scumming huge bets at gambling or the chicken races is definitely a way to get there, but you usually want a bit of capital before you start doing that.

To get that initial capital I would recommend initially focusing your Virtue on the farm - as it'll provide a source of income, items for quests, and you should really start getting the business requests completed if you're going for 100%.

Eventually, you'll be able to plant Ginseng. These are 1x1 plants that grow very slowly, so I'd recommend applying fertilizer. With a maxed out farm, you can sell your batch of Ginseng for around just over 20 ryo depending on your yields. This is a great source of money early on and can be something that generates while your out doing other things around Kyo

It's also worth mentioning that you can only pay these off in 20 ryo increments when you receive a letter from the landlord, who will ask you to meet him at the Fushimi shrine. This shrine is located northeast of the Teradaya inn and directly north of the Komaki Dojo (Brawler trainer).

I'm not 100% certain with this, but the letter frequency seems to be tied to your 'Another Life' progression. I didn't get the final letter until I was at 30/35 in the Diligence Records - let me know if you notice any differently

EDIT: Shout out to Tozi Tiberius but I should mention that you have to actually read/open the letters that are delivered to you else the landlord won't show up at the shrine