noun
black-market loan with 50% interest every ten days
Slang term from the phrase 十日で五割 (tōka de gowari), meaning 50% interest over ten days. Refers to an illegal, high-interest loan, often associated with yakuza or underground lenders.
あの金融屋はトゴで金を貸しているらしい。
That moneylender apparently lends money at 50% interest every ten days.
トゴに手を出すと、あっという間に借金が膨らむ。
If you get involved with a 50%-per-ten-days loan, your debt balloons in no time.
ヤミ金 is a broader term for any illegal high-interest loan, while トゴ specifically refers to the extreme 50%-per-ten-days rate.
Derived from the phrase 十日で五割 (tōka de gowari, '50% in ten days'). The reading トゴ is a contraction of 十 (tō) and 五 (go).