If something embarrassing happens to you at karaoke your friends (or coworkers) will likely forgive you. To a large extent what happens at karaoke stays at karaoke. Nevertheless, you may want to avoid some of the common sources of embarrassment at karaoke. These include:
1. Picking songs you have no chance of singingThere's a big difference between songs you like and songs you can sing. If you've never tried to rap before chances are you're not a natural. If you don't speak Japanese — chances are you can't sing Jpop.
Consistently picking songs you can't sing can make your karaoke experience less fun.
2. Stealing a songIf you're at karaoke with close friends you can organize things however you want. If you go with Japanese coworkers you should share the remote control. Everyone should have a more or less equal chance to choose songs. Don't grab the mic and butt in on someone's song.
Nothing's worse than when the new gaijin in the office sings every song all night. Watch what others do. If everyone is taking turns — do the same.
3. Getting lostThis one happens more than you might imagine. When you leave your room to go to the washroom — remember your room number. The path to the washroom is often long and winding. Many karaoke only have men's washrooms on every second floor.
The last thing you want is to have to peak into 25 rooms like some kind of weirdo before you can find your room.
4. Breaking the equipmentKaraoke gets pretty wild — people dance, jump on chairs or decide to mosh in the karaoke box. Most karaoke establishments are tolerant of this. However, if you break something they will be angry and will call the police. The police will subsequently give you an option: pay (usually far more than the equipment is worth) or go to jail for some indeterminate period of time.
5. Being surprised by the billLet's say a Karaoke is charging 2500 yen per hour per person for an all-you-can-drink plan. You go with 5 friends for 4 hours. Over the 4 hours 5 other friends drop by for a few minutes to say hello. You will be charged for 10 people for 4 hours ~ 100,000 yen ($1250 USD).
Karaoke can be economical. It's also easy to run up thousands of dollars in bills. For this reason, it's a bad idea to go to Karaoke with 20 random people you ran into at a club. You might get stuck with the tab.
6. Criticizing someonePeople can be surprisingly sensitive about their singing. It's a bad idea to criticize someone's singing unless you're sure they don't care.
7. VanityIf you're an amazing vocalist people might notice and they might not. It's not cool to make everyone sit at attention while you sing. It's not a concert it's a party.
Mock vanity in the name of fun is absolutely expected at karaoke.