Bishonen Jump Syndrome, also known as Shoujo Jump Syndrome, is a specific trend in {{shonen}} (boy's) {{manga}} (and {{anime}}), aimed at attracting a female PeripheryDemographic through gratuitously {{bishounen}} character design.

The {{manga}} anthology magazine ''Weekly Shonen Jump'' (on which the US magazine ''Magazine/ShonenJump'' is based) has long been the best-selling manga magazine in Japan. Although it is targeted to boys, it has a large female PeripheryDemographic. Sometime in the mid-1990s, ''Shonen Jump'' realized the sales potential of this demographic, and began to deliberately court female readers via MrFanservice. Specifically, they took standard {{shounen}} all-male teams and simply made them into a CastFullOfPrettyBoys (an idea promptly picked up by {{shoujo}} as too good to waste on the guys). Traces of HoYay are often also added [[ShippingGoggles (if not, ]] [[YaoiFangirl the fangirls]] [[ShippingGoggles will see it anyway).]]

Among the first series to show this effect were ''Manga/YuYuHakusho'' and ''Manga/RurouniKenshin'' (albeit with the latter it was a deliberate choice by the ''mangaka''); compare the art in these to ''Manga/SlamDunk'' or ''Manga/GreatTeacherOnizuka'', which have old-school character designs. ''Manga/KatekyoHitmanReborn'', ''Manga/DGrayMan'', ''Manga/ThePrinceOfTennis'' and ''Manga/KurokoNoBasuke'' are probably the most blatant examples in recent times.

The fangirl-bait worked, sales went up, and the idea was promptly copied by other shonen magazines, to the extent that it is now more-or-less standard procedure. It is nonetheless often ridiculed by readers who prefer the older tough-looking art styles, who deride ''Shonen Jump'' as "Bishonen Jump" or "Shoujo Jump".

For more information, see [[ this essay]] or [[ this essay]] (the latter was originally in Japanese and is awkwardly translated but informative).