Hello. New here. Just got to say, thanks for all your work in translating and debugging this game!
Here's what I've noticed with the playthroughs.
The jobs:
Working Adult: Pay 40k/week, with optional part-time on weekends.
Pros: Biggest salary. Does not change play style when getting the good "little sister pregnant" ending. Cons: Starting max energy mid to low. Starting max vigor: Low. No free time blocks. Work day 11 hours, five days a week. Leaves little time to "play" with imouto, hunt for panties, etc. Biggest mandatory energy exertion, a whopping 35 points. (30 at work, 5 on the walk back home.)
Part-Time: Pay 25k/week, with optional part-time on weekends.
Pros: One free time block, allowing for walking the neighborhood (+1/2 max energy), raising trust by cleaning the apartment, and hunting panties without risk of being caught. Cons: Starting max energy and max vigor medium range. Playstyle changes to Working Adult after the good "pregnancy" ending.
Student: Allowance 15k/week, with optional part-time on weekends.
Pros: Starting max energy mid to high, spend most of the day with imouto, but in separate classes, short "work" days, leaving plenty of time to "play" at the end of the day with imouto. Cons: No free slots. Second lowest income. Playstyle changes to Working Adult upon getting the good "pregnancy" ending.
Bum: Allowance 10k/week. Optional part-time on weekends initially unavailable, but can be unlocked.
Pros: Three free time-slots. Lowest living expenses. (Imouto buys daily meals if player doesn't have enough stamina to follow her to the grocery store.) Playstyle changes to Working Adult with good "pregnancy" ending. Cons: Lowest income. Initial Max energy and Vigor very low, often too low to do anything but just sit around at home sleeping. Player character has little interest in Imouto and needs to be forced into getting his act together.
Trust:
Increased by; talking about trivial topics, watching TV, playing games (unless a bad roll like "oops, I owned my sister hard"), or bathing together.
Decreased by; talking about lewd topics, cuming inside after Imouto tells you not to (prior to good pregnancy ending), getting caught peeping, or hunting panties.
Sexual Interest:
Increased by; talking about lewd topics, bathing together, any erotic acts (even sneaking into her bed at night and fooling around), playing gal-game, lewd game, or pervert RPG, especially when a critical success roll occurs. ("We had a fantastic time together.")
Decreased by; decreases normally 1-5 points per day, decreased by bad erotic acts, anything where Imouto gets mad and ends the night-crawling session.
Warning: It is strongly recommended to raise these values via game-play. Using Cheat Engine to do so may result in unstable game-play.
Dialogue and bath options are predominately unlocked by Trust, but a high Sexual Interest unlocks the bath-sex options. Again, this requires raising trust and sexual interest by game-play. Artificially increasing these values with a cheat engine can have unpredictable results and ruin the states of prior save-games.
Night crawling: A lot of people are confused about this one. Going to bed with 21 or more stamina remaining has player character wake up approximately one hour later (between 2330 an 0100 hours) and can choose whether to tuck Imouto in or molest her. The scene can be ended prior to "molest" by clicking on the pillow that's on the sofa. Molest can be ended by clicking the "end scene" link. Having Imouto wake up before she's at 50% good will almost always result in her getting mad and ending the scene. Her "bad" meter reaching maximum will have the scene end, regardless of how sound asleep she is. The bad meter can be lowered by head pats and kisses. With a high enough sexual interest and trust level, she will actually like night crawling, but you still have to get her wet first...
Accessories/props.
Barbell: One time +5 max energy.
Exercise Machine: One time +10 max energy. (Stacks with barbell)
Comfy pillow: Used by Imouto. Does not increase time for night crawling, but puts her in a deeper sleep, allowing player character to do more before she wakes up.
Aphrodisiac: Puts Imouto into "V. Sensitive" state and starts sex-scene half-way into "good" bar. Essential for many "masturbation" scenes.
Male Potency drug: Increases max vigor by 1 and current vigor by 2, with a maximum max vigor of 9. Unless the time is frozen via outside game influence, using up all 9 vigor in one night is nigh impossible, even on weekends.
Meals:
Ramen: Free, +5 energy, causes Imouto to lose one rank of emotion. Good mood> Neutral.
Ingredients: 1000, +15 energy, takes long to cook.
Bento: 2000, +10 energy, precooked.
Stamina meal: 3000, +15 energy, +2 vigor.
Bad endings:
Exploding Imouto. Just piss her off, either with "danger noodle" or night crawling and being a bad lay when she's already in a bad mood.
Insemination: Imouto comes to player character and says she missed her period. Not enough money+trust+good mood, or choosing the "w-we're not sure yet" and she will run home, either miscarriage or abortion not specified and is never seen again.
Good endings: (Game play continues)
100 days. Simple. Just go through 100 days with Imouto without getting a bad end.
Panties: Collect all 20 panties. (See below)
Good "pregnancy" ending: When Imouto says she missed her period, accept the baby and have sufficient trust+money. Taking Imouto to the beach first, helps. Note that this gets harder with every play-through. Each new play-through requires an additional 200 points of trust to clear the hurdle.
Full ending: Clear all three of the above.
Panties collection: Player character thinks raiding Imouto's drawers is boring, so prefers to steal (and maybe masturbate over) her panties from the wash. Panties found are always random, and eventually when duplicates appear, the option to search again, once, displays. Panties 1-12 are found on weekday hunts. Panties 13-15 can only be found by cleaning house on weekends. When panty #15 is found, the game runs to the "all panties found" ending, giving you a 20/20 panties found board, showing some panties Imouto would never wear.
Prior to version 1.9, Imouto had a 100% chance of triggering the "pregnancy" ending if even one drop of cum found its way into her pussy, unless she was tricked into drinking the morning after pill during the three days it took her to find out. After 1.9, with the implementation of "safe" and "dangerous" days, it is possible to cum inside without triggering the pregnancy end on "safe" days, but save first as the chance is still there.
There's plenty more to discuss, but that's best to discover through playing.
Thanks again!