Plot Summary

The story of Kakegurui – Compulsive Gambler takes place at Hyakkaou Private Academy (私立百花王学園), one of Japan’s most prestigious schools where, unlike normal schools, the hierarchy is determined by gambling. The main protagonist is Yumeko Jabami (蛇喰夢子), a transfer student whose beautiful, innocent facade hides a psychotic addiction to gambling and high-stakes situations. With a keen intellect able to pierce through the elaborate cheating methods used by the most powerful students to rig games in their favor, Yumeko threatens to destroy the twisted hierarchy of the school simply for the thrill of it.

Source: Wikipedia

OST

There are 61 soundtracks across the 12 episodes of the TV anime. The styles are mainly jazz and electronic music.

Jazz functions:

  • Creates a debauched atmosphere of money squandered and pleasure indulged, while also conveying the characters’ arrogance and conceit (賭ケグルイ, 艶ヤカナ狂気, 華ヒラク蛇, 下卑タ笑ミ, 变ヨウ); also conveys silent, tense moods (兆シ)

Electronic music functions:

  • Emphasizes a character’s overwhelming, unshakeable confidence (昂ル)

Others:

  • Specifically for the duel with Mitari Yikishima (生志摩 妄): a tune for a woman who pursues death fearlessly like a cowboy in the West, for the Russian roulette that determines life or death, for the silent faith between Yumeko and Ryota (妄二欲ス, 生キ死ニノ際)

OP (deal with the devil): The leaping tempo combines with a bewitching vocal to express why a strong mind is the heart of the matter (肝心なの strong な mind), tightly aligned with the anime’s content.

ED (LAYon-theLINE): The chorus and strings intertwine to form a triumphal song of the winner, while leaving room for the next carnival.

Frame

The overall animation quality is mediocre — notable especially for a MAPPA production. Compared to the original manga, the aesthetic impact is significantly reduced. The wildly exaggerated facial expressions (顔芸) remain one of the work’s highlights.

Yumeko’s Gambling Notion

Variable Ratio Schedule

To understand why Yumeko loves gambling in a psychotic way, we need to know what kind of reinforcement schedule gambling operates on.

A schedule of reinforcement determines which occurrences of a specific response result in the presentation of a reinforcer (Wayne Weiten, Psychology: Themes and Variations, p. 245). In a casino game, the reinforcer might include the reactions of others, the degree of risk, one’s own principal, and so on. These factors influence how often the response occurs — namely, the pleasure gained from gambling.

Since gambling has its own unique characteristic — unpredictability — it is a kind of variable-ratio (VR) schedule. People involved in gambling do not know when they will win and get pleasure, thus:

With a variable-ratio (VR) schedule, the reinforcer is given after a variable number of nonreinforced responses. The number of nonreinforced responses varies around a predetermined average. (Wayne Weiten, Psychology: Themes and Variations, p. 246)

In comparison to fixed schedules, variable schedules tend to yield steadier responding and greater resistance to extinction. (Wayne Weiten, Psychology: Themes and Variations, p. 246)

In short: due to the variable-ratio schedule, all gamblers will continue gambling steadily once they have engaged, and the behavior will not easily disappear.

Dopamine

In the reinforcement schedule, dopamine plays the role of positive reinforcement — a reward signal that makes the behavior more likely to occur again in the future.

The uncertainty of gambling gives dopamine these properties:

According to the hypothesis proposed by Montague, Dayan, and Sejnowski, rewards that are expected do not produce a second phasic dopamine response in certain dopaminergic cells, but rewards that are unexpected, or greater than expected, produce a short-lasting increase in synaptic dopamine, whereas the omission of an expected reward actually causes dopamine release to drop below its background level. (Schultz W, “Neuronal Reward and Decision Signals: From Theories to Data,” 95(3): 853–951)

This explains why Yumeko abhors any way of pushing a gamble’s outcome toward certainty. In the duel with Mitari Yikishima, Yumeko senses that Mitari has no real interest in gambling — she is purely bent on death — and expresses her utmost contempt. What Yumeko enjoys is the process of gambling itself, whether by pure luck or by her possibly superior skill at cheating: neither makes the outcome certain. Her extreme risk-seeking may stem from specific dopamine receptor configurations, or from the risk-amplified neurobiology of adolescence. Research shows that adolescents and young adults take more risks than any other age group (Joe Magliano, “Why Are Teen Brains Designed for Risk-Taking?”).

Pain

When people encounter pain, endorphins are released from the pituitary gland and the central nervous system, inhibiting the transmission of pain signals. For Yumeko, the anxiety and pain of gambling are short-lived; endorphins then sustain her joy and passionate state. She may therefore have naturally high endorphin levels.

Conclusion

Yumeko Jabami may have a rare physique — specific dopamine receptor configurations and high endorphin levels. In pursuit of maximum pleasure, she ignores all risk. Combined with the mechanics of gambling itself — the variable ratio schedule — in every gambling session, Yumeko experiences the supreme pleasure of dopamine and endorphins being secreted in large quantities simultaneously.