Envisioning urban sustainability demands to embrace divergent values of various stakeholders. Implementation of policies realizing city's future visions needs support from a wide range of general public. Hence, merits of participatory approach to backcasting scenario-making have been noted. Although experimenting such approach should be more encouraged, it remains to be seen whether lay citizens can generate their scenarios with required level of rationale and soundness. This chapter addresses this important, but yet unexplored concern by taking two potentially contrasting perspectives. One is "divergence" found in processes where citizens express their pluralistic interests and preferences in an unconstrained manner. The other is "convergence" found in where such a diversified plurality is circumscribed and composed to engender in outcomes some form of converged context. A trade-off relationship may arise between these two and the chapter seeks if any balance can be upheld. To explore such question, a participatory workshop was held in Toyama city, Japan where a handful numbers of citizens envisioned in two separate groups their desirable future via backcasting city's sustainable features. In analyses, outcomes of both groups' scenarios were compared and also index of consistency-based text structures endogenous to the scenarios was quantitatively gauged by computational simulation technique. Findings suggest that while a broad spectrum of socioeco-

Designing backcasting scenarios is a powerful approach to the development of sustainable visions and pathways for governments or enterprises in the early stage of their policy‐making or strategic decision‐making process. To date, a number of scholars have proposed various backcasting methods, in which workshops are often used to reflect the voices of stakeholders. However, it is still a challenge to test the validity of scenarios because the process of designing backcasting scenarios is not transparent or shared among involved stakeholders. This also prevents reusing knowledge and intermediate outputs generated during the scenario design process. To solve these problems, this paper aims to develop a method for supporting a backcasting scenario design by introducing computational assistance. A scenario design support system called the sustainable society scenario (3S) simulator is used to visualize a scenario's logical sequence of the scenario in graph format. To demonstrate the proposed method, a case study for the city of Toyama, a Japanese municipality, was performed using three workshops with citizen participation. The results showed that two different scenarios, involving future visions and associated pathways, were developed by reflecting the diversified values of local citizens. The usage of the 3S simulator visualized the logical relations of the described scenarios, which consist of five blocks—problem definition, subgoals to achieve visions, measures to attain these subgoals, verification, and conclusions. This visualization is effective to increase the verifiability and reusability of the scenarios for evidence‐based policy‐making processes.

The plants which were taken for the present study are as follows; Juglandaceae Juglans Sieboldiana MAXIM. Moraceae Ficus Carica L. Humulus japonicus SIEB. et ZUCC. Urticaceae Boehmeria frutescens THUNB. Polygonaceae Polygonum Reynoutria MAK. Magnoliaceae Liriodendron Talipifera L. Rosaceae Eragaria nipponica MAK. Filipendula palmatct, MAXIM. Sanguisorba officinalis L. Leguminosae Sophora angustifolia SIEB. et ZUCC. Pueraria triloba MAK. Desmodium racemosum DC. Geraniaceae Geranium nepalense SWEET. Rutaceae Boenninghausenia japonica NAKAI. Euphorbiaceae Ricinus communis L. Aceraceae Acer Negundo L. Acer saccharinum L. Vitaceae Vitis vintifera L. Ampelopsis heterophylla SIEB. et ZUCC. Cissus japonica WILLD. Malvaceae Lav dera arborea L. Althaea rosea CAV. Hibiscus militaris CAV. Sterculiaceae Firmiana platanifolia SCHOTT. et ENDL. Araliaceae Aralia elata SEEM. Aralia cordata THUNB. Fatsia japonica DECNE. et PLANCH. Umbelliferae Peucedanum decursivum MAXIM. Borraginaceae Ehretia Dicksoni HANCE. var. japonica NAKAI. Verbenaceae Clerodendron, trichotomum THUNB. Cucurbitaceae Trichosanthes cucumerioicles MAXIM. Compositae Petasites japonicus MIQ. Petasites japonicus MIQ. f. purpurascens MAK. Petasites giganteus FE. SCHM. Rudbeck,ia laciniata L. Ligularia tussilaginea MAK.