Assumptions
- Solo operator
- 5–20 Korean and Japanese clients
- Monthly revenue KRW 5M–30M
Core
**Client management**: HubSpot Free CRM + Notion client dashboards **Proposals/contracts**: Notion + Docusign/HelloSign **Time tracking**: Toggl or Clockify **Invoices**: freee (Japan clients) + Samjeomsam / tax accountant (Korea) **Payments**: Stripe + TossPayments + PayPay **Communication**: Slack Connect (client shared channels) + LINE Official / KakaoTalk channels **Docs/deliverables**: Notion + Google Drive **AI**: Claude Pro + ChatGPT Plus (multi-project context) **Automation**: n8n (client DB + invoice/report automation) **Meeting recording/notes**: Notta / AutoMemo / CLOVA Note
Monthly cost
- HubSpot Free
- Notion $10
- Toggl Free–
- Claude + ChatGPT: $40
- Stripe/Toss: fees only
- Notta/AutoMemo: $10–20/month
- n8n: $10
- Tax accountant: KRW 150k (KR) + ¥30k (JP)
~KRW 300–400k/month total.
How to work well
- Standardize per-client Notion page + dashboard
- Time tracking is invoicing's foundation — log daily
- Invoice automation is the lifeline of agency work
- Auto meeting summaries 3x your follow-up speed
Pitfalls
- Different tools per client: management hell
- No time tracking: 20–30% billing leakage
- Manual tax invoice / Invoice System issuance: permanent end-of-month overtime
Solo agency = systems are survival. Invest in automation from day one.