So Wolf did the math and came out with 7.3 days, or 175 total hours, to reach level 14 and get all of Alexis' messages and animations.

To not waste energy you must spend it before it caps, which varies by level.

Level: Time: (to fill battery) Hours to Reach Level (from previous level)
0 1hr 40min n/a
1 1hr 50min 1hr 40min
2 2hr 3hr 20min
3,4 2hr 10min 5hr (Level 3) 6hr 40min (Level 4)
5 2hr 30min 8hr 20min
6 2hr 50min 10hr
7 3hr 10min 11hr 40min
8,9 3hr 30min 13hr 20min (Level 8) 15hr (Level 9)
10 3hr 50min 16hr 40min
11,12 4hr 10min 18hr 20min (Level 11) 20hr (Level 12)
13 4hr 30min 21hr 40min
14 Irrelevant 23hr 20min

Total Time: 175hr ~ 7.3 Days if spending energy ASAP

You get the same amount of pleasure points no matter what level, 1 every 10 minutes (albeit you need 20 for kissing). The difference is that you can go longer without having to log in to spend energy.

The issue I see is that this means that if you aren't spending energy as soon as you can (ex. go to sleep) then you are in danger of not reaching level 14.

Tips:

-Complete as many levels as possible in the first few days while they can be done multiple times a day.
-Weekend Tournaments might have event rewards of some sort. There will be 2 tournaments during this event. If no event items, no big deal, keep
grinding and leveling up. Save rubies if you feel you might need to spend them for energy, because energy refills are 1 ruby per energy, but it only lets
you fill the battery, no partial assists.
-By the 7 day mark (halfway through event) you should be on Pleasure Level 9, and past halfway through PL 10. Otherwise you're falling behind.
-REGARDING RUBIES: If you think you might need to spend rubies on energy, save up for the last day. One ruby will get you one energy, but you can only spend it to fill battery completely. This means if your battery is empty, and you're on PL 13, then it is 270 rubies to fill it completely, not 100!