I'll only list down the options and what you need to choose to increase Muko's favorability. The game also tracks Rainy's favorability, but I don't think it's used for anything in the game. I also list it down in the guide, although I mostly recommend choosing Muko whenever you are able.

For the ones listed as impossible to get, you just need to choose other options. I only list it down in case Episode 2 is released so you can choose that option whenever that time comes.

The guide will be in this format:

Act <number>
<option a|option b|...> -> which option you need to choose (additional info)

If I write <option a> + <option b>, it means you can choose both.

Example:

Act 11
<Yes|No> -> Do nothing (doesn't raise favorability, but will lead to the option below)

It means that during Act 11, if there is an option to choose Yes or No, just Do nothing. Do nothing means that you let the timer runs out.

The game also tracks other variables (Hypocrisy, Persistence, Friendship, Chinese, Math, and English). I won't list these options. If you need them (and options that lead to optional achievements, which I also don't cover), you can use this guide instead: https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2082080326
Basically, just use this and that achievement guide and choose the listed options as you play. You can choose any options if it's not listed in both guides; it means the result won't change anything.

In order to get the good ending, you'll need Persistence > 0, Friendship > 0, and Muko's favorability > 15. If the story doesn't end at Act 33, then you are on the good ending route. There is no difference in the script between both ending otherwise - the story up to Act 33 is the same.

• You can get Persistence in Act 14 at the earliest. During the last part of the exam, wait until the timer runs out.
  
• You can get Friendship in Act 2 at the earliest. During <Yes|No> option with Chang where he asks you about your confession, choose Yes.

Yes, both of them are listed on the achievement guide I linked above.

In order to get the Green Apple ending, you'll need Muko's favorability > 18 in Act 42. If you want to read the text for that ending, just see the gamefile:

<game folder location>\Diary_Data\StreamingAssets\Story\English\Stories\ending1.story

You can reach the game folder location by Right click on the game in your Library > click Properties > click the Installed Files tab > click Browse...
There should be a Windows Explorer opening up that directs you to a LoveDiary folder. From there, just go to Diary_Data > StreamingAssets and so on until you find the ending1.story file. Right click on the file and choose Open and then choose any text editor you have (Notepad is fine).

I'm not sure how it works in Linux and Mac, but it should more or less the same. You just need to find the file location and use another text editor since those OS has no Notepad installed as default.

Act 3
<Ask her tentatively> -> Do nothing (1/24)
<Diverge from topic> -> Diverge from topic (2/24)

Act 4
<Yes|No> -> Yes (Rainy favorability, no option for Muko)

Act 5
<Of course|No> -> No or Do nothing (Of course will increase your favorability with Rainy) (3/24)
<grateful|deskmate fellowship> -> Do nothing (the other options will increase your favorability with Rainy) (4/24)

Act 6
Mr. Gao's Class -> Rainy + Muko (choosing Rainy will increase your favorability with Rainy) (5/24)

Act 8
<Tell her|Don't tell> -> Tell her (6/24)
[National holiday day 2 -> Go for a walk] <To chat with her|Only watching her from distance> -> Only watching her from distance (Rainy favorability, no option for Muko)
<hand her the letter|don't> -> hand her the letter (7/24)
<Petrel|Jian> -> Do nothing (8/24)

Act 11
<Yes|No> -> Do nothing (doesn't raise favorability, but will lead to the option below)
<Yes I do|I don't> -> I don't (9/24)

Act 12
<I would do the same|bye> -> I would do the same (need Muko's favorability >9, impossible to get. ref.) (24/24)

Act 13
Mr. Gao's Class -> Muko (choosing Rainy will increase your favorability with Rainy) (10/24)
Who are you thinking about now? (Nightmare Maze) -> Muko (choosing Rainy will increase your favorability with Rainy) (11/24)

Act 14
<I will|have a guese?> -> I will (12/24)

Act 18
Class -> Muko (choosing Rainy will increase your favorability with Rainy) (13/24)

Act 20
<Muko|Chang|Rainy> -> Muko (choosing Rainy will increase your favorability with Rainy, choosing Chang will increase your Friendship) (14/24)
Mr. Gao's Class -> Muko (15/24)

Act 21
<buy hat first|go hold her hand> -> Do nothing (16/24)

Act 22
<Yes|No> -> Yes (bugged in English and Japanese version)

Act 24
<persistance makes succeed|try next time> -> persistance makes succeed (17/24)

Act 28
<probe|express further> -> express further (18/24)

Act 29
<try date her|don't be straightforward> -> try date her (19/24)

Act 31
<I was rejected by Tsinghua|I was dumped by you> -> I was dumped by you (20/24)

Act 33
<give myself to you|nothing> -> give myself to you (21/24)

Act 34
Choosing where to go next -> Gift shop -> Pink cashmere rabbit gloves (Muko's favorability will be increased on Act 36) (22/24)

Act 41
<because you helped me|because feeling> -> because feeling (23/24)