Originally a particularly polite way of saying “you,” the Japanese word otaku evolved into a label for anyone with an obsessive, passionate devotion to their hobby. While most commonly associated with anime fans, the term is also applied to hardcore video gamers, technology buffs, and even auto enthusiasts.

Much like “geek,” otaku was initially a derogatory term, but has lost a lot of its sting and become largely co-opted in recent years. Still, it’s important to not let yourself get too wrapped up in your hobbies. Conveniently, there’s now a mathematical formula to determine if your otaku-ness has become too much for your own good.

The Nomura Research Institute, an offshoot of investment house Nomura Securities, recently published a study on consumer spending. Among the categories the data was broken down into was “otaku hobbies,” which was further refined into a number of sub-classifications for soft otaku (anime, video games, manga comics), hard otaku (computer and audio/video equipment), outdoor otaku (cars, cameras, trains, travelling), and fashionable otaku (clothing, celebrity-related merchandise/event tickets).

▼ Complete sets of Arashi fans don’t come cheap, after all.

A few of these, such as fashion and travel, aren’t traditionally considered otaku activities, given their respective goals of interacting with others (even if only to show off your new threads) and getting out of your apartment to see the world. Still, for the purposes of the study, the Nomura Institute seems to have broadly classified otaku expenditures as any intensive discretionary spending.

Based on this definition, financial planner Shunsuke Yamasaki, a self-admitted manga otaku, has developed an easy mathematical test to determine if your otaku hobbies are having an adverse effect on your economic well-being. The formula for calculating your otaku coefficient, as Yamasaki calls it, is as follows:

otaku coefficient = (monthly expenditures on otaku hobbies ÷ (monthly pre-tax income) X 100

Yamasaki pegs an acceptable, socially responsible otaku coefficient as being equal to or less than 10. Above that, things start moving towards a danger zone, with the temptation to run up credit card bills and make use of Japan’s ubiquitous payday advance loan agencies and their absurdly high interest rates. Should an individual’s otaku coefficient rate reach a whopping 20, Yamasaki urges them to rethink their lifestyle and budgeting priorities, lest they end up like my college classmate who, upon arriving in Japan, financed his love of manga by cutting out more traditional expenditures such as lunch.

▼ Yeah, I suppose the incomplete development of the hero’s journey in this pork cutlet bowl does make for a disappointing narrative. On the other hand, I’m really fond of protein.

By the way, our math-savvy readers will notice that despite the fancy name, Yamasaki’s formula is simply calculating what percentage of your pre-tax income you spend on otaku hobbies. This is true, but ignores the fact that “otaku coefficient” sounds much cooler, and if there’s one thing otaku love, it’s specialized vocabulary. As proof, mention giant robot Gundam’s “laser sword” to any hardcore fans, then watch as they sigh in exasperation and explain that it’s called a “beam saber.”

▼ Then give them a moment to catch their breath so they can explain how the correct term isn’t “giant robot,” but “real robot.”

Sources: Jin, Urepia Research