https://www.patreon.com/user?u=2548758

Direct sequel for https://e-hentai.org/g/2487410/409e46e88d/

Base +6

Actual apneist here: besides the obvious, general "do not try this at home" disclaimer, do not try to use this doujin for advice of apnea techniques. Specifically do NOT ever do the hipervenilating thing of page 80. This empties your lungs of residual CO2, which seems a good idea but is actually incredibly dangerous.

Short version: You may actually DIE if you do that.

Long version: What causes you to feel you are out of breath is an high C02 level, not a low level of oxygen. By decreasing the baseline level of CO2, you REALLY risk passing out WITH NO WARNING from having depleted all your oxygen without having ever noticed you were out of air.

Base +16, Neo-Exile +10, SevenStation +12

If you breathe hard in and out can't it make you black out on purpose?

Base +12