Shoju

Shoju is an extremely early-budding sencha cultivar found on a single Kuritawase bush on Tanegashima, the Kagoshima island famous for shipping Japan’s earliest new tea of the year, and registered under the Plant Variety Protection Act in 1996. It exists because of a mutation, not a breeding programme: a Tanegashima grower, Matsushita Eiichi, noticed a branch on an existing Kuritawase plant behaving differently from the rest of the bush, propagated cuttings from it, and found the resulting plants bred true to the new trait. Where most cultivars in this collection trace to a research station’s crossing block or a farmer’s seedling field, Shoju traces to neither — it is Kuritawase with one branch’s worth of difference, fixed by cuttings rather than by seed.

Lineage

• Kuritawase (くりたわせ / 栗田早生) — the single bush Shoju arose from. Kuritawase contributes essentially everything: Shoju’s extreme earliness, its adaptation to Tanegashima’s mild climate, and the base of its flavour, since Shoju differs from it in only the handful of traits the mutation changed.

This is a sport (枝変わり, literally “branch change”), not a seedling and not a cross. A seedling — like Yabukita, or like Kuritawase itself in its own origin — grows from a seed and is genetically a new individual, mixing two parents’ genes in a way that cannot be repeated. A sport is the opposite: it is a spontaneous mutation that appears somewhere on an already-growing, clonally propagated plant, so the mutated branch is genetically identical to its parent bush except for whatever the mutation changed. Propagate cuttings from that branch, as Matsushita did, and every resulting plant carries the same single difference and nothing else new. Shoju therefore has no seed parent and no pollen parent to record — only the one bush of Kuritawase it branched from — and unlike a cross, its “parentage” is not a combination but a near-identity, several steps closer to its source than any seedling could be. No cultivar bred forward from Shoju was found in the sources consulted, and none of the master registries checked list it as a parent of anything else.

History

The Kurita family and Kuritawase

Kuritawase’s own origin is unusually well documented for a cultivar this obscure, thanks to a commemorative stone inscription at Furuta Banyamine in Nishinoomote City, Tanegashima, transcribed on the local history site furusato-tanegashima.net. According to that inscription, the grower Kurita Mosaburo ordered Shizuoka zairai (native) seed in Meiji 42 (1909) and sowed it in a seedling tea garden on Tanegashima. His son, Kurita Seiichi, selected 60 promising individual stocks from that seedling field in Taisho 10 (1921) and carried out further individual surveys of the best of them in 1926. In Showa 2 (1927), Sugiyama Hikosaburo — the same grower who, two decades earlier and a very different island away, had selected Yabukita from a Shizuoka zairai stand — visited Tanegashima and, under his guidance, the family selected a single outstanding stock from among the survivors. Cuttings from that one plant were propagated, and several dozen were planted at the Kagoshima prefectural tea experiment station in 1931. Recommended-cultivar trials ran from 1952 to 1959, and a comparative sencha-quality trial against other early cultivars followed in 1965; on the strength of those results, Kuritawase was designated Kagoshima Prefecture’s recommended cultivar (県奨励品種) in Showa 41 (1966) and spread through the island’s early-harvest districts. By the end of fiscal 1983, the inscription records 75 hectares under cultivation. Kuritawase has never held a national Cha Norin registration; myjapanesegreentea.com’s cultivar list places it explicitly among Japan’s unregistered tea cultivars.

The broader context matters here: the 1909 migration that brought Kurita Mosaburo’s zairai seed to Tanegashima was part of a wider wave. A Shizuoka-born official who had served on Tanegashima recognised the island’s suitability for tea and urged tea-growing families back home to relocate there; among those who did, in the same year, was Matsushita Sukeshichi — founder of the family that would breed Shoju three generations later.

A sport found at Furuta

Matsushita Eiichi, Sukeshichi’s great-grandson and the fourth generation of the family to farm tea on Tanegashima, found and propagated the branch mutation that became Shoju on Kuritawase growing at Furuta — the same district as the Kurita family’s own monument. He filed a Plant Variety Protection Act application on 9 August 1993 (application no. 6225) and the variety was registered on 18 March 1996 as registration no. 4952, in his own name, at his address in Furuta, Nishinoomote City. No source found gives an earlier date for when the mutated branch was first noticed, so a discovery year distinct from the 1993 application cannot be stated with confidence. The registry’s own record shows an 18-year statutory term for the breeder’s right, but also records that right as lapsed on 19 March 1998 — see rarity above; no source explains the gap.

The cultivar is named, according to local reporting picked up by both a Yokohama FM radio feature and Japanese Wikipedia, for Shojuin (松寿院), said to have been an aunt of Atsuhime within the Tanegashima clan. Today the Matsushita family sells Shoju, alongside Kuritawase and several other cultivars, under the Tanegashima Shojuen (種子島松寿園) brand — a retail operation Matsushita built up himself after decades of shipping only unfinished bulk tea (荒茶), motivated by a complaint that comes through clearly in a Tanegashima University interview with him: the district’s tea wins on speed to market and, he insists, on flavour, but has never won on name recognition the way Kagoshima’s Chiran does. Shojuen tea is now exported to Germany and Switzerland.

Characteristics

Shoju buds and is picked extremely early (極早生) — the earliest of the ten-plus cultivars grown on Tanegashima, with new growth appearing from around February and first picking typically under way by mid-March, timed to open Japan’s earliest new-tea season each year. Its own official MAFF variety description gives a detailed plant profile: tree form slightly open; vigour, stool spread and leaf-layer thickness medium; at harvest, shoot uniformity, shoot number and picked-shoot length medium, with a somewhat low number of unfurled true leaves per shoot and a small hundred-bud weight. New leaves are elliptical, small, somewhat thin and pale green; mature leaves are elliptical, medium-sized, with quite few surface wrinkles and little edge waviness. Branching is frequent with short internodes, cutting propagation roots at a medium rate, and yield in both young and mature bushes is rated somewhat low. Against Kuritawase specifically, the registration notes Shoju as distinguished by a thicker leaf layer, more shoots at harvest, an elliptical (rather than Kuritawase’s own) mature-leaf shape, and fewer leaf-surface wrinkles; against Yabukita, by its more open tree form, smaller new leaves, elliptical mature leaves, fewer wrinkles, and its markedly earlier budding and harvest.

The same official description rates the finished product’s shape as medium, colour medium-to-upper, aroma and liquor colour superior, taste medium-to-upper, and total nitrogen and amino acid content abundant — chemistry consistent with a fuller, more umami-forward cup. Tasting notes outside the registration converge on one unusual descriptor: a golden liquor with a milky, vanilla-like sweetness that local sources repeatedly describe as unlike any other tea cultivar, alongside a clean, rounded finish. One published tasting reaction — “milk-like!!!! the flavour is round, and sweet… maybe this is what tea’s version of milk tastes like” — captures the reaction the cultivar tends to provoke from tasters encountering it for the first time. No source found gives disease-resistance or cold-hardiness data for Shoju specifically. As a sencha-only registration confined almost entirely to Tanegashima, it remains a minor cultivar nationally, but locally it is treated as a point of pride: the tea that, every March, is the first in Japan to reach market.