Representation of larger-than-life phalluses is one of shunga's most memorable features. Such depiction is often explained to have originated in so-called kachi-e, a painting of a phallic contest (yōbutsu kurabe) among men with surrealistically huge male members. However, what kachi-e precisely is, including its origin, evolution, and range of variety has been left unstudied. This article's aim is to document kachi-e's development from the earliest known form through its variations over the centuries, as well as to consider how the perception and depiction of this theme changed in visual and literary sources. The initial focus is on the oldest extant kachi-e example, Kachi-e emaki preserved in the Mitsui Memorial Museum in Tokyo, which consists of two parts: a phallic contest and farting battles (höht gassen). The Mitsui handscroll is most likely a combination of two faithful copies of medieval originals. Literary sources of the medieval period provide some insight into attitudes towards having a large phallus, but indicate no specific benefit physiologically or personally. Fascination for kachi-e continues throughout the Edo period until the early Meiji era. The current Mitsui handscroll was highly appreciated due to its attribution as Toba Sōjō's authentic work and copied by prominent artists with antiquarian interests, while innovative versions of phallic contests were created, in which having a large phallus was positively valued. In some later versions female protagonists are poised on the other side of men in an "intercourse battle." These new elements indicate that the kachi-e were appropriated into popular shunga discourse in the Edo period. These new phallic contest representations also kept the original humorous tone with an ironical view towards the common admiration of large male genitals.