Father was in debt ?
It's implied in the movie that the father was in debt:
1. Weird guy coming to see him;
2. Father seem to put money on games;
3. The fact he wanted 65k asap;
4. The crisis and his death after he couldn't get it;
But I Don't think it's said explicitly. What do you think ? I'm 99% sure it had Nothing to do with opening a restaurant.