Pagoda Tree (Sophora japonica), known as "Huai Hua" in Traditional Chinese Medicine (TCM), has a long history of use primarily for conditions such as bleeding disorders (e.g., hemorrhoids, blood in stool) and vascular health. Its flowers and buds are rich in flavonoids like rutin and quercetin, which exhibit anti-inflammatory and vascular-protective effects. However, its use specifically for irritability is rooted more in traditional practice and TCM theory rather than scientific validation. In TCM, irritability is often interpreted as a manifestation of "heat" or "liver fire," and some practitioners may use Pagoda Tree in formulas aimed at "clearing heat" or calming the spirit. Despite this, there is no robust scientific research directly linking Pagoda Tree or its active compounds to the alleviation of irritability as understood in a Western medical context. Most available studies focus on its anti-inflammatory, antioxidant, and vascular effects, rather than mood or neuropsychiatric symptoms. Therefore, its use for irritability is justified by tradition, but the supporting evidence is weak and largely anecdotal.