Dialogue density in anime

An ordinary least-squares regression of franchise density on AniList genres, source material, format and air year (n = 1,635) gives R² = 0.19. Genres alone give R² = 0.11 and source material 0.09; format and year add little.

The largest coefficient is for light-novel source: +22.7 morae/min relative to manga (SE 2.3), with genre, format and year held fixed. Retention of first-person narration from the source text is one possible explanation; it is not tested here. Among genres, Comedy has a coefficient of +14.9 (SE 1.8) and Horror −21.6 (SE 4.2).

Density is weakly correlated with popularity (Spearman ρ = 0.13) and uncorrelated with mean AniList score (ρ = 0.02).

AniList tags

Tags are user-voted and more specific than genres. For each tag on at least 25 franchises (relevance of 60% or more), the chart shows the mean regression residual of the tagged franchises, that is, the association with density beyond genre, source, format and year, together with the unadjusted difference in medians.

The largest positive residuals are for Meta (+18.9), Parody (+16.1) and Satire (+14.3); the largest negative for Iyashikei (−16.3), Steampunk (−13.2) and Fairy (−12.5). Tags overlap, so these estimates are not independent of one another.

Dialogue density is the product of speaking rate, the morae per second while a dialogue caption is on screen, and dialogue coverage, the share of runtime with a dialogue caption on screen: density = 60 × rate × coverage. Caption timing conventions differ between subtitle sources, so this section uses only the 582 franchises with Netflix captions, which follow a single timing guideline.

In a decomposition of the variance of log density across these franchises, coverage accounts for 55%, speaking rate for 27%, and their covariance for 20%. The Disastrous Life of Saiki K., the highest-density franchise in this subset, ranks 1st in speaking rate and 8th in coverage.

Mean density in 15-second bins over 31,389 episodes with a runtime of 23 to 25 minutes. Lyrics are excluded from the counts, so opening and ending sequences appear as troughs. Density reaches its maximum of 229 morae/min at about minute 6 and declines gradually to about 205 by minute 20. Commercial breaks fall at different points in different series and leave no distinct trough in the mean. The small rise after the ending sequence is consistent with next-episode previews.

Median density by the main animation studio of each franchise's first season, for studios with at least 10 franchises. Lines show the interquartile range. Studio medians range from 164 (Toei Animation) to 226 (EMT Squared).

Directors and series-composition writers

Median density for staff credited on at least 6 franchises, with each franchise counted once. Medians conceal wide individual ranges: Masaaki Yuasa has the lowest director median (158 morae/min), although his The Tatami Galaxy (296) is among the highest-density franchises in the corpus.

Seasons are dated by their own air year. The median of yearly medians is 185 morae/min for 2000–2009 and 196 for 2020 onward. Over the same period the share of seasons adapted from light novels, the source with the highest adjusted density, rose from 11% to 26%.

In the franchise-level regression above, with genre and source held fixed, the year coefficient is +1.6 morae/min per decade (95% CI −0.2 to +3.4). The raw increase is therefore consistent with a change in the composition of what is produced rather than a general change in scripting.

Vocabulary load is the number of the corpus's most frequent lemmas needed to cover 95% of a franchise's word tokens, excluding proper nouns and numerals. Lemma frequencies are averaged over franchises with equal weight. The median load is about 6,000 lemmas, and load is nearly uncorrelated with dialogue density (Spearman ρ = 0.09).

The Tatami Galaxy and Food Wars! are high on both measures. The Disastrous Life of Saiki K. has the highest density among popular franchises but a below-median load. Girls' Last Tour is low on both.