Really, she hadn't planned on going. She'd known Obito's birthday was coming up (she remembers everyone's birthdays, annoying as it is), but had neither expected to be invited to the event, nor expected to go in case someone remembered she was the reason they even had a Godaime.
Then those two magical words "open bar" had appeared on the unexpected letter that had, somehow, found her before the date of the party. For a brief, wry second, Tsunade had wondered if she were really so easy to manipulate, that even a Hyuuga she had only met twice knew her weakness. Then the following seconds were filled with travel preparations, because open bar.
(And if the open bar isn't the only reason she goes, well. She'll never admit it.)
Tsunade is actually there long before Obito himself arrives, hitting the bar like it owes her money. Of course, it would take more alcohol than is even in the training ground to get her drunk, but she can enjoy the fare while it lasts, can't she?
[open]
Then those two magical words "open bar" had appeared on the unexpected letter that had, somehow, found her before the date of the party. For a brief, wry second, Tsunade had wondered if she were really so easy to manipulate, that even a Hyuuga she had only met twice knew her weakness. Then the following seconds were filled with travel preparations, because open bar.
(And if the open bar isn't the only reason she goes, well. She'll never admit it.)
Tsunade is actually there long before Obito himself arrives, hitting the bar like it owes her money. Of course, it would take more alcohol than is even in the training ground to get her drunk, but she can enjoy the fare while it lasts, can't she?