Oxygen Lounge Juko

In this minimalist space, an attendant seats guests along a row of self-serve tanks that pump exotically flavored oxygen, from eucalyptus menthol to cinnamon, into your lungs; choose from 10-minute (600 yen/$6) and 20-minute (1,200 yen/$12.50) sessions. The benefit? You decide—many claim increased oxygen eases headaches, induces alertness, and even reduces the effects of jet lag.