The science
The relevant chemistry here is a standard oil-in-water emulsion architecture: glycerin and butylene glycol as the humectant phase doing the immediate hydration work, mineral oil as the occlusive lipid providing the post-application water-loss barrier, and a sorbitan isostearate / sucrose stearate / polysorbate 60 emulsifier system holding the two phases together as a stable cream-lotion. The cosmetic-chemistry literature supports this as one of the most well-validated emulsion templates available — it's the same architecture used in countless successful pharmacy-brand moisturizers from CeraVe to Cetaphil to Eucerin.
The glycerin position deserves a brief mechanistic note. Glycerin works by osmotic water draw into the upper stratum corneum, pulling water both from the dermis below and from ambient humidity above (in environments with sufficient relative humidity). The published evidence on glycerin's effect on skin hydration is robust — at concentrations from 3% upward, glycerin produces measurable improvements in corneometry readings within 30 minutes of application. The Naturie formula's high glycerin position (second in the INCI, behind only water) suggests a concentration in the 5-10% range, which is well within the effective dose-response window.
The mineral oil deserves a defensive note given its popular reputation. Cosmetic-grade mineral oil is one of the most thoroughly tested ingredients in cosmetic chemistry, with consistent evidence supporting non-comedogenicity in human use and excellent safety profile. The widespread fear of mineral oil in skincare is not supported by the published evidence and largely originates as a marketing artifact created by botanical-oil brands competing for shelf space. As an occlusive, mineral oil reliably reduces transepidermal water loss by approximately 30-40%, which is mechanistically why this emulsion holds hydration through extended wear.
The hatomugi extract has a thinner evidence base. Coix lacryma-jobi has been studied for in-vitro tyrosinase inhibition (relevant to brightening claims) and modest anti-inflammatory activity from compounds including coixenolide. The published research is predominantly preclinical and uses isolated compounds at concentrations often higher than what cosmetic formulations include. In this leave-on emulsion the extract has meaningful contact time on skin, which is a better delivery context than the rinse-off Hatomugi cleansing products — but expecting clinical-grade brightening from a likely sub-1% extract concentration is not supported by current evidence.
The methylparaben preservative deserves a brief honest note. The published safety evidence on methylparaben at cosmetic concentrations is robust and reassuring — concerns about parabens primarily stem from a now-largely-discredited 2004 study on breast tissue. Current regulatory and dermatological consensus is that methylparaben at the concentrations used in Japanese drugstore products is safe and effective. Personal-policy paraben avoidance is reasonable; scientific paraben fear is not particularly well-supported.