What truly made the animation "better" was the sound design. Most fans remember the "Rain Episode." Instead of heavy dialogue, the studio used the rhythmic thrum of a summer downpour against the metal railings to build tension. The animation of the rain—each drop splashing against the grey concrete—was so fluid it felt hypnotic.
If you're comparing it to the live-action version (JAV/drama), the anime allows for more exaggerated expressions and scenarios. But if you expect fluid, cinematic animation, it may disappoint. ano danchi no tsumatachi wa the animation better
The preference between the manga and anime adaptation of "Ano Danchi no Tsumatachi wa" largely depends on personal taste: What truly made the animation "better" was the sound design