Informal communication plays a vital role in corporate activities but is often constrained in remote work environments. This study investigates the current state of remote informal communication (RIC) in a Japanese corporate setting and identifies key issues across age groups. Results show that junior employees often feel anxious and hesitant to speak, while senior employees tend to refrain from participating due to concerns about hierarchy and age-based norms. To address these issues, this paper introduces GrowChat, a gamified system incorporating collaborative character creation (CC) and character development (CD). The system aims to promote spontaneous conversation and lower psychological barriers to RIC. Experimental findings suggest that CC facilitates initial engagement, while CD supports sustained, self-directed communication. These results indicate that GrowChat may effectively enhance RIC in Japanese corporations.