I'm borrowing the idea of the 'Info Vault' from Random Usagi.
If you guys want to contribute or add any link, feel free to leave a comment below ^^

Official website and SNS:

The lead actors:

Haru is currently a member of the J-pop group Bullet Train.

Where to watch:

The series has still not been released on an official platform for international fans. In Japan it is temporarily available on TVer, TBS Free and Netflix. If you download the NekoCap extension (and a VPN if you don't live in Japan), you can watch it on TVer and TBS Free with English captions. See Borax's thread for more info.

Official OST

The theme song is "U&I" by Hi-Fi Un!corn. The single is available on many streaming platforms, such as Spotify or YouTube Music. Check out the complete list here.
The official MV with scenes from the series:


Shuto, who plays Yokouchi in the series, is one of the vocalists of Hi-Fi Un!corn. Here is a live performance of "U&I" with Shuto as the main focus:


The original manga:

"Kimi ni wa Todokanai" (also known as "I Cannot Reach You") is based on a Japanese manga of the same name written and illustrated by Mika. In Japan it's released by MFC Gene Pixiv Series and published by Kadokawa. The English edition is published by Yen Press.

Drama merchandise: 

You can find the official merch on TBS's online shop: https://shopping.tbs.co.jp/tbs/shop/goods_dvd/drama_kiminai.

Shooting locations:

You can check out the shooting locations used in each episode here (the blog is in Japanese): https://asikotz.com/entertainment/drama/kiminai/#outline__3_1.

A little bit contributes to you, the OST is "U & I" from an idol boy band Hi-Fi Un!corn, but the song release date is still TBA

Currently, Oshiroen is English fansubbing it, here's the link: https://t.co/qzHUZiKMRi

If it's available on TVer or any official platform, I'll add it here later

Ay you made it! Looks nice ^^

Sasuga F! We're back in business. GOnna 

 Gouki:

A little bit contributes to you, the OST is "U & I" from an idol boy band Hi-Fi Un!corn, but the song release date is still TBA

Currently, Oshiroen is English fansubbing it, here's the link: https://t.co/qzHUZiKMRi

If it's available on TVer or any official platform, I'll add it here later

Thank you. I'm just waiting for the song to be released so I can add it to EP1

 Gouki:

A little bit contributes to you, the OST is "U & I" from an idol boy band Hi-Fi Un!corn, but the song release date is still TBA

Currently, Oshiroen is English fansubbing it, here's the link: https://t.co/qzHUZiKMRi

If it's available on TVer or any official platform, I'll add it here later

Thank you for the extra help, Gouki ^^

 RandomUsagi:

Ay you made it! Looks nice ^^

Awww, thank you so much!!! <3 I couldn't ignore the request XD

 Borax:
Sasuga F! We're back in business.

Ahahah yayy

 Gouki:

A little bit contributes to you, the OST is "U & I" from an idol boy band Hi-Fi Un!corn, but the song release date is still TBA

Currently, Oshiroen is English fansubbing it, here's the link: https://t.co/qzHUZiKMRi

If it's available on TVer or any official platform, I'll add it here later

Update: Release Date of the OST will be 29/11

 Nicksden:

Nice work, F <3

Thank you so much, Nick <33333

Aside from Netflix JP, TVer will stream each episode on TVer for 1 week, and unlike Netflix, TVer requires VPN only

https://tver.jp/series/srzeym5a68 

 Gouki:

Update: Release Date of the OST will be 29/11

Early release for “U&I” (VPN required) for YouTube Music, Spotify, etc

https://linkco.re/t430YYc0?lang=en

It's now up on YT 

Hi-Fi Un!corn (ハイファイユニコーン) 「U&I」

https://www.youtube.com/watch?v=iiJQCkKTkhY

Haru's group also released a new MV today lol 

超特急「Lesson ll」MUSIC VIDEO

https://www.youtube.com/watch?v=cj4xzX10htY

Lyrics. I'm gonna send Oshiro karaoke effects to put on his subs.