Methodology

Big Five Personality Traits

The Big Five (OCEAN model) is the most widely accepted personality trait model in modern psychology. Decades of factor analysis research have repeatedly confirmed that human personality can be described along five independent dimensions.

Our site evaluates how similarity and complementarity in each trait affects relationship satisfaction, based on findings from the Malouff et al. meta-analysis (integrating 19 studies covering 3,848 couples).

• Agreeableness - The trait most strongly correlated with relationship satisfaction
• Emotional Stability - Both partners' stability directly impacts relationship quality
• Conscientiousness - Aligned lifestyle habits contribute to long-term stability
• Extraversion - Evaluates compatibility of social styles
• Openness - Intellectual curiosity and value resonance

Age Gap Statistics

Multiple large-scale statistical studies exist on the relationship between age gaps and relationship longevity. We incorporate findings from Emory University research (3,000 participants) and Japan's Ministry of Health, Labour and Welfare vital statistics data.

However, age gap statistics represent population-level trends and do not predict outcomes for individual couples. Many couples with significant age differences maintain happy, lasting relationships.

Zodiac (Element Compatibility)

We incorporate the four-element compatibility theory (Fire, Earth, Air, Water) from Western astrology as a reference value. While reflected in the assessment, this serves as a supplementary indicator independent of the scientifically-grounded primary evaluation axes.

Blood Type (Reference)

Large-scale surveys (10,000+ participants) have found no statistically significant relationship between blood type and personality. Considering Japanese cultural context, we include this as a reference value with minimal weight. Blood type input is optional and excluded from evaluation if not provided.

Overall Assessment

Multiple evaluation axes are integrated through our proprietary algorithm to determine overall compatibility on a scale from SSS to G. Rather than simple numerical addition, we perform multidimensional evaluation considering interactions and complementary relationships between traits.

When optional items are left blank, evaluation is performed using only the provided inputs. The analysis can be completed with Big Five responses alone.

References

• Malouff, J. M., Thorsteinsson, E. B., Schutte, N. S., Bhullar, N., & Rooke, S. E. The Five-Factor Model of personality and relationship satisfaction of intimate partners: A meta-analysis. Journal of Research in Personality, 44(1), 124-127.
• Nawata, K. No relationship between blood type and personality: Evidence from large-scale surveys in Japan and the US. Japanese Journal of Psychology, 85(2), 148-156.
• Ministry of Health, Labour and Welfare, Japan - Vital Statistics