1. Escaping the 2nd or 3rd PartyTokyo izakaya and restaurants often have a 2 hour time limit during peak hours. It's common for parties to jump from place to place as the night goes on. These are affectionately called 1st, 2nd and 3rd parties.
The 1st party is often laid-back. A bit of relaxation after work or class at a restaurant or izakaya.
The 2nd party may take place at a izakaya, bar or karaoke. It's considerably more silly than the 1st party.
A few people usually escape the 2nd party. It's also common to leave in the middle of the 2nd party. Experienced locals know it's often better to disappear from the 2nd party without saying goodbye (otherwise you'll get dragged back in).
The third party is usually at a bar, karaoke or club. Depending on the group, many people may escape the 3rd party. Those who don't escape often wish they had the next day.
2. Making the Last TrainTokyo nightlife is driven by ticking clock — the dreaded last train. Making your last train ensures that you'll be fit for work (or life in general) the next day. Missing your last train can mean a big taxi fee to get home.
3. Taking a CabIf you miss last train — the best option is often to take a taxi. Depending where you live this can cost up to 25,000 yen ($300 USD). For many people, it's less than 10,000 yen.
4. Crashing in a Capsule / Business HotelFor people who live a distance from central Tokyo, staying the night in a capsule or business hotel can be an economical option. If you plan to go to work the next day, you'll have to wake up for first train (~ 5:30 AM) to return home for a change of clothing. Otherwise, just buy a different color tie from a convenience store (or even a vending machine) so that your coworkers will think you changed.
Capsule hotels provide pajamas.
5. Crashing in a Manga Cafe or KaraokeThis is a popular option to catch a few hours sleep while you wait for your first train. Manga Cafes and Karaoke are generally safe and comfortable enough. There are people living in manga cafes.
6. Making the First TrainMany people who miss their last train end up partying all night. Be sure to take it easy and make your first train.
People often camp out at fast food joints waiting for first train.
7. Napping in PublicThe worst case scenario is becoming so intoxicated that you end up sleeping in public.
Sleeping in public is one of the 7 deadly sins of Japan travel.