use discount ticket

Hello, i have a few question about [Osaka City Subway to Kansai int'l Airport]@discount ticket 1000Yen.
i'm from (subway tanimachi 9 chome) want to go to kansai international airport, but i want to exit namba station to go to dotonbori before going to kansai airport. Is it valid to use this discount ticket to exit namba station before going to kansai airport??

Is it valid to use this discount ticket to exit namba station before going to kansai airport??

Yes. You need to do the trip on the same day, but you can stroll around Namba as much as you want, after you exit the ticket gate of the subway and before entering the ticket gate of Nankai railways (to KIX).

The mentioned discount ticket is called in Japanese as Kanku Chikatoku Kippu.

You can use this ticket as long as you have a subway train ride until Namba and a Nankai train ride from Namba on the same day;
however, this ticket saves only 100 yen for your case, and it does not cover the Nankai Limited Express surcharge for a Rapi:t train ride from Namba, which is 510 yen.

When you choose Nankai Rapi:t, the following discount tickets are better cost-wise.
- Kanku Tokuwari Rapi:t Ticket
http://www.howto-osaka.com/en/ticket/ticket/tokuwari.html
- Kanku-WEBTOKU Ticket
http://www.howto-osaka.com/en/ticket/ticket/webtoku.html

Seats in a Nankai Rapi:t train require reservation; as long as there is vacancy, your can secure your seat.

[With regular tickets only]

(A) 180 yen
: Subway basic fare to get from Tanimachi 9-chome [Kyuu-chome] to Namba.
(B) 920 yen
: Nankai basic fare to get from Namba to Kansai-airport.
(C) 1100 yen = (A) + (B)
: Minimum cost.
(D) 510 yen
: Nankai Limited Express surcharge for Rapi:t train ride from Namba.
(E) 1610 yen = (C) + (D)
: Cost to be paid when you choose Nankai Rapi:t.

[With "Chikatoku" ticket and Nankai Limited Express ticket]

(R) 1000 yen on the discount ticket, instead of (C).
(S) 1510 yen = (R) + (D)
: Cost to be paid when you choose Nankai Rapi:t.

[With "Tokuwari" ticket and Subway basic-fare ticket]

(T) 1270 yen on the discount ticket, instead of (B) + (D).
(U) 1450 yen = (A) + (T)
: Cost to be paid when you choose Nankai Rapi:t.

[With "WEBTOKU" ticket and Subway basic-fare ticket]

(W) 1130 yen on the discount ticket, instead of (B) + (D).
(X) 1310 yen = (A) + (W)
: Cost to be paid when you choose Nankai Rapi:t.