They're an odd lot aren't they, but that video has it wrong (although the girl says she hasn't ever bought a can and doesn't know for sure what is inside).
What you actually get inside the can is a voucher for a one-hour interview and advice session from a company called MAP (Matching Advisor Press). It’s a matchmaking service for singles seeking a serious relationship that will hopefully lead to marriage (konkatsu). There are pink cans from women seeking a relationship and beige ones from men, each can having the age of the person concerned printed on it. If MAP deems you a potentially suitable match they charge a further 9,000 yen (about $60) to arrange a three-hour dinner date, with you paying the additional cost for food and drinks.