Interest Stacks

Firefighting

Ancient Egypt (1500 B.C.)

Music (violin)

Historical artwork and techniques (Italy, 1500s)

Medical
Some focus on performing first aid in war zones and desolate areas.

Italian cuisine, Italian language in kitchen context

Music
Ch 12: Learning notes

Art, Painting(s)

Really nice if you can recognize actual paintings, such as "Meisje met de parel/Girl with the pearl earring" in Ch 7 p7

Carting (racing)

Psychology

Medical

General scientific info about surviving in the Stone Age.
Preserving foods, create tools, make your situation better from the beginning, be creative and smart with the small and little things you have.

Penguins

Travelling around Japan in 1878, from the viewpoint of an enthusiastic foreigner.

Farm Animals - agricultural school (not far enough to give a better explanation yet)

Free Diving

Russo-Japanese War (~1900), Ainu culture & survival know-how, Russian + translation to English (Vol 17-20), some relevant historical individuals in that time

Boxing

Human physiology and biology on the cellular level

Go (board game)

Martial arts
Ch 57

Books, scriptures and concerned materials

Note: this is a fantasy manga, but that is because it's an isekai and the writing system is fictional, together with the settings.

However the parts that are thoroughly explained by the author should be useful.

Mind games, psychological warfare and violence, thinking outside the box

Car racing

Drugs, medicines, diseases
Some focus on antibiotics, the black death (caused by Yersinia pestis), vitamin C deficiency also known as scurvy for sailors, toxic lead in cosmetics...

Survival tips on an island cut off from the rest of the world

Irish and American history (1800s), (coffee roasting Ch 3, whale hunting Ch 8, smallpox Ch 9, corn Ch 10, St. Patrick's Day: March 17th Ch 11)

(Mountain) climbing information

Drugs, medicines, diseases

Medical, first aid (do not attempt this kind of advanced first aid if you're not a medical professional)

Tips and tricks about cleaning

Firefighting & Rescue

Bacteria & other micro-organisms

Masking murder

Parts of it won't be of much use to you but it's still interesting

General knowledge, some fun facts or good-to-know-information

Mountain climbing information

Cleaning: Ch 4 & 11
There is some supernatural stuff but the difference between info usable irl is clear

Post-WWII Japan: the dark side

Various clothing in all of history
(haven't checked this but it looks real informative)

Agriculture and other medical information

Basketball

Medical

Ch 42 is A+ still the most frequent blood type in Japan nowadays? => According to Wikipedia it is, with almost 40% who have type A (and rhesus positive is way more common than rhesus negative regardless of the location).

There are exceptions but it seems that most in America, Europe and Africa have O+, and most in Asia have A+; both of them are the two most common blood types in almost any country.

Ch 43: ABO-blood type categorization + Lewis blood type categorization (less used but still important)

(https://en.wikipedia.org/wiki/Blood_type_distribution_by_country)

Biology of insects and bugs

Miscellaneous info, regarding weapons or the hitman life.

Latin, Roman & Japanese bathing

Criminology and toxicology

Space

Salvors and sea/water related rescue

Cycling

Books, strolling around a regular library's inner mechanics