百花百狼 戦国忍法帖 (English title: Nightshade)
Developer: Red Entertainment Corporation & Lantern Rooms
VNDB Play Time: 30h
VNDB Link: 百花百狼 戦国忍法帖
Character count: 492k (from someone who finished it)
Number of weeks to finish: 20-22 weeks
Summary
From VNDB:
Thanks to an age of constant war, the Iga and Kouga had independently achieved an expansion of their respective forces.
Both shinobi forces, owing to that long history of warring, shared an antagonistic relationship of mutual hatred towards one another. However, during the ninth year of the Tenshou era, the Iga forces fell into ruin due to the Tenshou Iga War started by Oda Nobunaga. The few Iga members that had survived were taken in by the Kouga forces.
Seventeen years later, the Sengoku period had ended and lasting peace came to the world.
Dreaming of performing shinobi duties, Ueno Enju (the protagonist), daughter of the Kouga forces’ leader, Ueno Kandou, had been training everyday.
After finally being selected to go on her first mission, a major incident occurs. It not only derails Enju’s fate, but the fate of the village as well…
[Translation of the official website’s story summary.]
Availability
Steam
Switch: JP US EU
PS vita (JP release) (not sure if it is possible to get new still, can’t figure it out)
Personal Opinion
Who can resist ninjas? This is an otome, aka protagonist is a woman and she’s dating men. So it is historical Japan. According to Steam’s description, the story is fiction, but there are real historical figures and events sprinkled in it. Nightshade is set a few years after the sengoku war ended.
I’m hoping there is a lot of ninja goodness with romance. It just sounds like a lot of fun to me.
It is a bit long for the club, but all the otome I’m interested in that had more story rather than just pure dating seems to be this length. 
It seems to have 5 routes with two endings each. Not sure if there is a true path/ending.
And according to @Belerith (link to post):
Pros and Cons for the Book Club
Pros
- Ninja
- Historical Japan
- Seems to have chapters (according to a screenshot at VNDB)
- Fully voiced except protagonist
- Romance
- Many endings
Cons
- Time and subject specific vocabulary
- It might be a little too long to be read within this club’s parameters (max 25k character per week, max time allowed 5 months), meaning speed might need to be higher from the beginning or increase after a couple of months
- According to reviewers: Not all routes are as enjoyable and the romance is better than the plot
- Has bad ending(s)
- Many endings
Pictures
Screenshots
Not sure these show the range of language, but I can’t seem to find any other good ones.
Difficulty Poll
How much effort would you need to read this VN?
- No effort at all
- Minimal effort
- Moderate effort
- Significant effort
- So much effort my head might explode
- I don’t know